How to use Groups in a sentence
In the Ader transmitter as many as twelve carbon pencils were employed, arranged in a series of two groups with six pencils in parallel in each group. These were supported at their ends in parallel carbon bars, which were carried by a nearly horizontal wooden diaphragm.
And all these groups, while talking among themselves, tried to keep near the commander-in-chief (whose bench formed the center of the gathering) and to speak so that he might overhear them.
Groups of people will do science this same way.
Here and there were groups of houses that seemed made of clear glass, because they sparkled so brightly.
I never had patience to arrange more than five or six groups at a time.Advertisement
Groups of singers stood outside the windows.
Talal paused in an open doorway leading to a large, green field behind the dwelling occupied by hundreds, perhaps thousands, of warriors organized into sparring groups of four and five.
The men led her into a large meeting hall with warriors clumped in small groups throughout the hall.
Some left, ignoring her, while others shifted between small groups.
She followed the group down several corridors into a massive conference room filled with people in tight groups talking.Advertisement
Climbers could be seen in pairs, groups and singles, some nearly beneath them.
The groups of boys stopped upon seeing Elisabeth and elbowed each other.
Groups of people milled and moved towards the fields surrounding the town, guided by moonlight and the light of handheld lanterns.
Lanterns lit the underground, and people huddled in quiet groups.
Many of the bikers knew one another and there were groups traveling together, but there was equal representation of couples and solo bikers.Advertisement
Three bedrooms and one bath — not much of a dude ranch, but she intended to rent the house out to small groups.
Dozens of men sparred in small groups along the cliff.
The Daltonian would say that each of these weights represents a certain group of atoms, and that these groups can replace, or combine with, each other, to form new molecules.
Considering the wide differences between the two groups in the size and external characters, and in the mode of life, including the mode of feeding, it is indeed surprising that in every important organ the two groups should show a fundamental morphological identity.
These two groups are divided by the deep valley of the Tirso, the only real river in Sardinia, which has a course of 94 m.Advertisement
There are three distinct though connected groups of ruins at Zimbabwe, which are commonly known as the "Elliptical Temple," the "Acropolis" and the "Valley Ruins."
Groups of these dwellings are enclosed by subsidiary stone walls so as to form distinct units within the larger precinct.
Apart from the above-mentioned division of the striped members of both groups into two types according to the pattern of their markings, the domesticated cats of western Europe are divided into a short-haired and a long-haired group. Of these, the former is the one which bears the closest relationship to the wild cats of Africa and of Europe, the latter being an importation from the East.
Two principal groups are distinguished, the Kuri archipelago in the south, and the Buduma in the north.
It is adminis- Groups.Advertisement
The cotton industry is distributed in three principal groups.
Other groups of less importance are situated in the Lyonnais (Roanne and Tarare) and Mayenne (Laval and Mayenne).
Theoretically, no doubt, this is correct, but the typical members of the two groups are so different from one another that, as a matter of convenience, the retention of the two families seems advisable.
Sammetblende or przibramite is a variety, from Przibram in Bohemia, consisting of delicate acicular or capillary crystals arranged in radiating groups with a velvety surface and yellow colour.
European geographers have been accustomed to divide the islands into three groups for purposes of nomenclature, calling the northern group the Parry Islands, the central the Beechey Islands and the southern the Coffin or Bailey Islands.
Faringdon House, close to the church, was built by Henry James Pye (1745-1813), poet laureate from 1790 to 1813, who also caused to be planted the conspicuous group of fir-trees on the hill east of the town called Faringdon Clump, or locally (like other similar groups) the Folly.
And when he writes in eight parts for a double chorus the two groups are seldom identioal.
Beneath the epidermis is a longitudinal layer of muscle-fibres which are separated into four distinct groups by the dorsal, ventral and lateral areas; these are occupied by a continuation of the epidermic layer; in the lateral areas run two thin-walled tubes with clear contents, which unite in the anterior part of the body and open by a pore situated on the ventral surface usually about a quarter or a third of the body length from the anterior end.
Such a plasmodium bears, on its periphery, groups of rounded projections of protoplasm termed end-organs.
The parasitic Nematodes include by far the greatest number of the known genera; they are found in nearly all the orders of the animal kingdom, but more especially among the Vertebrata, and of these the Mammalia are infested by a greater variety than any of the other groups.
For political purposes these are subdivided into eight subordinate groups, consisting of three residencies and five agencies.
As late as the accession of Assur-bani-pal and Samas-sum-yukin we find the Babylonians appealing to their city laws that groups of aliens to the number of twenty at a time were free to enter the city, that foreign women once married to Babylonian husbands could not be enslaved and that not even a dog that entered the city could be put to death untried.
In practice the number of segments actually employed is much greater than that indicated on the figure, and the segments are arranged in a number of groups, as shown by fig.
As many as 162 segments in eight groups are practically used.
Again, suppose groups 3 and 4 to be punched.
The operator actuates a typewriter form of perforator which punches varying groups of holes, representing the different characters, in a paper strip about one inch wide.
In one of these ways the oscillations can be created or stopped at pleasure in the radiating antenna, and hence groups of electric waves thrown off at will.
The subscribers' lines in an exchange are arranged in groups of moo, which are divided in turn into sub-groups of 100 each.
The congeries of small groups of lower hills in the north are known as the Hessische Bergland.
But the Apennines of Central Italy, instead of presenting, like the Alps and the northern Apennines, a definite central ridge, with transverse valleys leading down from it on both sides, in reality constitute a mountain mass of very considerable breadth, composed of a number of minor ranges and groups of mountains, which preserve a generally parallel direction, and are separated by upland valleys, some of them of considerable extent as well as considerable elevation above the sea.
Nor do the highest summits form a continuous ridge of great altitude for any considerable distance; they are rather a series of groups separated by tracts of very inferior elevation forming natural passes across the range, and broken in some places (as is the case in almost all limestone countries) by the waters from the upland valleys turning suddenly at right angles, and breaking through the mountain ranges which bound them.
The northern part of Tuscany is indeed occupied to a considerable extent by the underfalls and offshoots of the Apennines, which, besides the slopes and spurs of the main range that constitutes its northern frontier towards the plain of the Po, throw off several outlying ranges or groups.
The whole of the district known in ancient times as Samnium (a part of which retains the name of Sannio, though officially designated the province of Campobasso) is occupied by an irregular mass of mountains, of much inferior height to those of Central Italy, and broken up into a number of groups, intersected by rivers, which have for the most part a very tortuous course.
It maybe also divided into three groups.
Parliament had degenerated into a congeries of personal groups, whose members were eager only to overturn cabinets in order to secure power for the leaders and official favors for themselves.
No concession could be denied to deputies, or groups of deputiec, whose support was indispensable to the life of the cabinet, nor, under such conditions, was it possible to place any effective check upon administrative abuses in which politicians or their electors were interested.
The closing of the French market to Sicilian produce, the devastation wrought by the phylloxera and the decrease of the sulphur trade had combined to produce in Sicily a discontent of which Socialist agitators took advantage to organize the workmen of the towns and the peasants of the country into groups known as fasci.
Com posed mainly of elements drawn from the Left, and dependent for a majority upon the support of the subversive groups of the Extreme Left, the formation of this cabinet gave the signal for a vast working-class movement, during which the Socialist party sought to extend its political influence by means of strikes and the organization of labor leagues among agricultural laborers and artisans.
On the principle of contradiction this division is both exhaustive and exclusive; there can be no overlapping, and no members of the original genus or the lower groups are omitted.
The Udgatri's duties being mainly confined to the chanting of hymns made up of detached groups of verses of the Rigveda, as collected in the Samaveda-samhita, the more important Brahmanas of this sacerdotal class deal chiefly with the various modes of chanting, and the modifications which the verses have to undergo in their musical setting.
Between the Andamans and Cape Negrais intervene two small groups, Preparis and Cocos; between the Andamans and Sumatra lie the Nicobar Islands, the whole group stretching in a curve, to which the meridian forms a tangent between Cape Negrais and Sumatra; and though this curved line measures 700 m., the widest sea space is about 91 m.
In the same year the two groups, Andaman and Nicobar, the occupation of the latter also having been forced on the British government (in 1869) by the continuance of outrage upon vessels, were united under a chief commissioner residing at Port Blair.
At present, therefore, classifications of the Hydromedusae have a more or less tentative character, and are liable to revision with increased knowledge of the life-histories of these organisms. Many groups bear at present two names, the one representing the group as defined by polyp-characters, the other as defined by medusa-characters.
Groups founded on polypcharacters are printed in ordinary type, those founded on medusacharacters in italics.
Ocelli are seen at the base of the tentacles, and also (as an exception) groups of medusiform buds.
The coenosarc may consist of a single elongated tube or stolon, forming the stem or axis of the cormus on which, usually, the appendages are arranged in groups termed cormidia; or it may take the form of a compact mass of ramifying, anastomosing tubes, in which case the cormus as a whole has a compact form and cormidia are not distinguishable.
The various types of appendages described in the foregoing may be arranged in groups termed cormidia.
The observation that large groups of species of widely different habits present the same fundamental plan of structure; and that parts of the same animal or plant, the functions of which are very different, likewise exhibit modifications of a common plan.
Buffon (1753-1778), at first a partisan of the absolute immutability of species, subsequently appears to have believed that larger or smaller groups of species have been produced by the modification of a primitive stock; but he contributed nothing to the general doctrine of evolution.
Taking into account existing animals and plants alone, it became obvious that they fell into groups which were more or less sharply separated from one another; and, moreover, that even See the " Historical Sketch " prefixed to the last edition of the Origin of Species.
At the present moment it is impossible to draw up any definition, based on broad anatomical or developmental characters, by which any one of Cuvier's great groups shall be separated from all the rest.
The result is, on the one hand, a clearing away of much fantastic phylogeny, on the other, an enormous reduction of the supposed gaps between groups.
The archipelago is divided into two groups - the Leeward (lies sous le Vent) and the Windward Islands (Iles du Vent) - by a clear channel of 60 m.
To the west lie the small groups of coral islets - Mopiha (Lord Howe), Ura (Scilly) and Bellingshausen (discovered by Otto von Kotzebue, 1824).
Milne-Edwards removed the Polyzoa; the group was soon further thinned by the exclusion of the Protozoa on the one hand and the Entozoa on the other; while in 1848 Leuckart and Frey clearly distinguished the Coelenterata from the Echinodermata as a separate sub-kingdom, thus condemning the usage by which the term still continued to be applied to these two groups at least.
This surface layer in the typically subaerial shoot of the sporophyte in Pteridophytes and Phanerogams is known as the epidermis, though the name is restricted by some writers, on account of developmental differences, to the surface layer of the shoot of Angiosperms, and by others extended to the surface layer of the whole plant in both these groups.
In a second type they are situated at the ends of tracheal strands and consist of groups of richly protoplasmic cells belonging to the epidermis (as in the leaves of many ferns), or to the subjacent tissue (the commonest type in flowering plants); in this last case the cells in question are known as epithem.
One of the most striking characters common to the two highest groups of plants, the Pteridophytes and Phanerogams, is the Vascular possession of a double (hydrom-leptom) conducting .s system, such as we saw among the highest mosses, YS em.
It is confined to the sporophyte, which forms the, leafy plant in these groups, and is known as the vascular system.
In the other groups of Pteridophytes internal phloem is not found and an internal endodermis but rarely.
The vascular supply of the leaf (leaf-trace) consists of a single strand only in the haplostelic and some of the more primitive siphonostelic forms. In the microphyllous groups Leaf.trace of Pteridophytes (Lycopodiales and Equisetales) in and Petlolar which the leaves are small relatively to the stem, the Strands, single bundle destined for each leaf is a small strand whose departure causes no disturbance in the cauline stele.
Another kind of differentiation in such a cell-mass as we are dealing with is the setting apart of particular groups of cells for various metabolic purposes.
The proteolvtic enzymes, or those which digest proteids, are usually divided into two groups, one which breaks down ordinary proteids into diffusible bodies, known as peptones, which are themselves proteid in character.
It is, of course, impossible to do this here, but I will briefly discuss one or two groups of cases.
The former is concerned with the division of the earths surface into major districts characterized by particular plants or taxonomic groups of plants, with the subdivision of these floristic districts, and with the geographical distribution (both past and present) of the various taxonomic units, such as species, genera, and families.
The types of vegetation (tropical forests, sclerophyllous forest, temperate forests, tundra, &c.) thus briefly outlined are groups of Schimpers climatic formations.
Such groups are interesting in that they are vegetation units whose physiognomy is, in a broad sense, related more to climatic than to edaphic conditions.
Hence, in any cosmopolitan treatment of vegetation, it is necessary to consider the groups of plant communities from the standpoint of the climatic or geographical district in which they occur; and this indeed is consistently done by Schimper.
It is true that in the unicellular plants all the vital activities are performed by a single cell, but in the multicellular plants there is a more or less highly developed differentiation of physiological activity giving rise to different tissues or groups of cells, each with a special function.
The union of the germ nuclei has now been observed in all the main groups of Angiosperms, Gymnosperms, Ferns, Mosses, Algae and Fungi, and presents a striking resemblance in all.
F, Separation of the chromosomes into two groups G, Chromosomes grouped at opposite ends of the spindle to forn the daughter nuclei.
Moreover, had the evolution of plants proceeded along the line of adaptation, the vegetable kingdom could not be subdivided, as it is, into the morphological groups Thallophyta, Bryophyta, Pteridophyta, Phanerogamia, but only into physiological groups, Xerophyta, Hygrophyta, Tropophyta, &c.
We owe to Buffon the recognition of the limitation of groups of species to regions separated from one another by natural barriers.
If we add to the latter figure the families which are widely dispersed, we find that the tropics possess 161 or almost exactly two-thirds of the large groups comprised in the worlds vegetation.
Thus in the Mediterranean region the large groups of palms, figs, myrtles and laurels are each only represented by single surviving species.
Instead of large continuous areas, in which local characteristics sometimes blend, it occupies widely dissevered territories in which specialization, intensified by long se1/2aration, hai mostly effaced the possibility of comparing species hnd even genera and compels us to seek for points of contact in groups of a higher order.
The classification of the land surface into areas inhabited by distinctive groups of plants has been attempted by many phytogeographers, but without resulting in any scheme of general acceptance.
Sclater have been found to hold good for a large number of groups of animals as different in their mode of life as birds and mammals, and they may thus be accepted as based on nature.
Professor Keane groups man round four leading types, which may be named the black, yellow, red and white, or the Ethiopic, Mongolic, American and Caucasic. Each may be subdivided, though not with great exactness, into smaller groups, either according to physical_; characteristics, of which the form of the head is most important, or according to language.
The hydrogen of the hydroxyl group in phenol can be replaced by metals, by alkyl groups and by acid radicals.
Hantzsch (Ber., 1901, 34, p. 3337) has shown that in the action of alcohols on diazonium salts an increase in the molecular weight of the alcohol and an accumulation of negative groups in the aromatic nucleus lead to a diminution in the yield of the ether produced and to the production of a secondary reaction, resulting in the formation of a certain amount of an aromatic hydrocarbon.
The keel has been lost, and is being lost, at various epochs and by various groups of birds.
In most birds the feet of the coracoids do not touch each other; in some groups they meet, in others one overlaps the other, the right lying ventrally upon the left.
In birds of various groups the clavicles are more or less degenerated, the reduction beginning at the distal end.
The humerus with its crests, ridges and processes, presents so many modifications characteristic of the various groups of birds, that its configuration alone is not only of considerable taxonomic value but that almost any genus, excepting, of course, those of Passeres, can be " spotted " by a close examination and comparison of this bone.
The three middle metatarsals become fused together into a cannon bone; the upper part of the third middle metatarsal projects behind and forms the so-called hypotarsus, which in various ways, characteristic of the different groups of birds (with one or more sulci, grooved or perforated), acts as guiding pulley to the tendons of the flexor muscles of the toes.
He was, however, the first to show clearly that the Ratitae are the retrograde descendants of flying ancestors, that the various groups of surviving Ratitae are, as such, a polyphyletic group, and he has gone fully into the interesting question of the development and subsequent loss of the power of flight, a loss which has taken place not only in different orders of birds but also at various geological periods, and is still taking place.
The loss has taken place, and still takes place, independently in widely different groups.
These are instances, now well understood, that almost every organic system, even when studied by itself, may yield valuable indications as to the natural affinities of the various groups of birds.
This fact alone is sufficient proof that these conditions, or rather reductions, have been acquired independently of the various groups.
It is no exaggeration to say that the genus, often even the species, can be determined from almost any recent bone, but in the case of Miocene, and still more, of Eocene fossils, we have often to deal with strange families, which either represent an extinct side branch, or which connect several recent groups with each other.
Our artificially-established classifications collapse whilst we gain further insight into the mutual affinities of the existing groups.
The key to the distribution of recent groups lies in that of the extinct forms. Not only have many absolutely new families been discovered, but many kinds of modern birds are now known to have existed also in countries which they are now extinct.
Birds being of all animals most particularly adapted for extended and rapid locomotion, it became necessary for him to eliminate from his consideration those groups, be they small or large, which are of more or less universal occurrence, and to ground his results on what was at that time commonly known as the order Insessores or Passeres, comprehending the orders now differentiated as Passeriformes, Coraciiformes and Cuculiformes, in other words the mass of arboreal birds.
It is therefore just as much the business of the zoogeographer, who wishes to arrive at the truth, to ascertain what groups of animals are wanting in any particular locality (altogether independently of its extent) as to determine those which are forthcoming there.
Besides these, three or perhaps four groups, though widely distributed throughout the world, arrive in the Australian region at their culmination, presenting an abundance of most varied forms. These are the weaver-birds (Ploceidae), and the moreporks (Podargidae), but especially the kingfishers (Alcedinidae) and the pigeons (Columbidae), the species belonging to the two last obtaining in this region a degree of prominence and beauty which is elsewhere unequalled.
Besides the three larger islands numerous satellites belong to the subregion, as Lord Howe, Norfolk and Kermadec islands, with the Chatham, Auckland and Macquarie groups.
To these follow the tanagers (Tanagridae), with upwards of forty genera (only one of which crosses the border), and about 300 species; the piculules (Dendrocolaptidae), with as many genera, and over 200 species; the ant-thrushes, (Formicariidae), with more than thirty genera, and nearly 200 species; together with other groups which, if not so large as those just named, are yet just as well defined, and possibly more significant, namely, the tapaculos (Pteroptochidae), the toucans (Rhamphastidae), the jacamars (Galbulidae), the motmots (Monotidae), the todies (Todidae), the trumpeters (Psophiidae), and the screamers (Palamedeidae); besides such isolated forms as the seriema (Cariama), and the sun-bittern (Eurypyga).
For narrow as are the channels between Cuba and the opposite coast of Central America, between the Bahamas and Florida, and between Grenada and Tobago, the fauna of the Antillean chain, instead of being a mixture of that of the almost contiguous countries, differs, much from all, and exhibits in some groups a degree of speciality which may be not unfitly compared with that of oceanic islands..
The close affinity of North America with the Palaearctic avifauna becomes at once apparent if we exclude those groups of birds which we have good reason to believe have their original home in the Neotropical region, notably numerous Tyrannidae, humming-birds and the turkey-buzzards.
The resulting " classification is based on the examination, mostly autoptic, of a far greater number of characters than any that had preceded it; moreover, they were chosen in a different way, discernment being exercised in sifting and weighing them, so as to determine, so far as possible, the relative value of each, according as that value may vary in different groups, and not to produce a mere mechanical ` key ' after the fashion become of late years so common " (Newton's Dictionary of Birds, Introduction, p. 103).
It is not the quantity but the quality of the anatomical and bionomic characters which determines their taxonomic value, and a few fundamental characters are better indications of the affinities of given groups of birds than a great number of agreements if these can be shown to be cases of isomorphism or heterophyletic, convergent analogy.
It follows that new groups of Ratitae can no longer be developed since there are no Carinatae living which still retain so many low characters, e.g.
It is more nearly related to modern Siamese than to modern Shan, but possesses many groups of consonants which have become simplified in both.
On the east and west faces of the base are two great stone groups of Peace and War respectively.
To the north of Heng-chow Fu detached groups of higher mountains than are found in the southern portion of the province are met with.
The glands occur in groups, and lead into common ducts which open usually so much reduced that the foremost apparent ventral sclerite of the abdomen represents the third sternite.
The distribution of many groups of beetles is restricted in correspondence with their habits; the Cerambycidae (longhorns), whose larvae are wood-borers, are absent from timberless regions, and most abundant in the great tropical forests.
Such obvious features as the number of segments in the foot and the shape of the feeler were used by the early entomologists for distinguishing the great groups of beetles.
Students of the Coleoptera have failed to agree not only on a system of classification, but on the relative specialization of some of the groups which'.
The total valuation is then divided into three equal parts, representing three groups of electors very unequal in number, each of which elects an equal number of delegates to the municipal duma.
When workmen from any province come, for instance, to St Petersburg to engage in the textile industries, or to work as carpenters, masons, &c., they immediately unite in groups of ten to fifty persons, settle in a house together, keep a common table and pay each his part of the expense to the elected elder of the artel.
There were no great, well-organized secret societies, but there were many small groups, composed chiefly of male and female students of the universities and technical schools, which worked independently for a common purpose.
The growth of railways has been accompanied by a world-wide tendency toward the consolidation of small independent ventures into large groups of lines able to aid one another in the exchange of traffic and to effect economies in administration and in tl-_e purchase of supplies.
These in turn converge to a pair of single lines which lead to two groups of marshalling sidings, called " gridirons " from their shape, and these again converge to single lines leading to " lower reception and departure lines " at the bottom of the slope.
The chief groups, all yielding coco-nuts, pandanus fruit and yams, are Funafuti or Ellice, Nukulailai or Mitchell, Nurakita or Sophia, Nukufetau or De Peyster, Nui or Egg, Nanomana or Hudson, and Niutao or Lynx.
Prayer ends, as it began, the banquet; and we break up not in bands of brigands, nor in groups of vagabonds, nor do we burst out into debauchery..
Thus the term Savaii itself, originally Savaiki, is supposed to have been carried by the Samoan wanderers over the ocean to Tahiti, New Zealand, the Marquesas and Sandwich groups, where it still survives in such variant forms as Havaii, Hawaiki, Havaiki and Hawaii.
The Spaniards were entrenched, with their heavy artillery distributed along the front, but, thanks to Navarro, they had a more mobile artillery in the shape of 200 arguebuses d croc mounted in groups upon carts, after the German fashion, and this was held ready to move wherever its services might be needed.
The labours of Golgi, Marchiafava, Celli and others established the nature of the parasite and its behaviour in the blood; they proved the fact, guessed by Rasori so far back as 1846, that the periodical febrile paroxysm corresponds with the development of the organisms; and they showed that the different forms of malarial fever have their distinct parasites, and consequently fall into distinct groups,.
The number of persons was 78, and they were divided into two equal groups of 39 each.
In 16thcentury sculpture the cathedral is especially rich, containing many statues, groups and altar-reliefs by Simone Mosca and Ippolito Scalza.
The elders of these groups possessed some influence, and tended to form an aristocracy, which took the lead in social life, although their authority generally depended merely upon custom.
Their names vary in origin and probably also in point of age, and where they represent fixed territorial limits, the districts so described were in some cases certainly peopled by groups of non-Israelite ancestry.
Collections of laws are found in Deuteronomy and in exilic and post-exilic writings; groups of a relatively earlier type are preserved in Exod.
The vegetation is similar to that of Fiji, but more definitely Indo-Malayan in character; it embraces all the plants of the groups to the east with many that are absent there.
The greater part of the island is occupied by ranges of mountains which form four principal groups.
The principal groups are for the greater part of the year covered with snow, which remains in the deeper clefts throughout the summer; the intervals between them are filled by connecting chains which sometimes reach the height of 3000 ft.
Of the more conventional side of Late Minoan life a graphic illustration is supplied by the remains of miniature wall paintings found in the palace of Cnossus, showing groups of court ladies in curiously modern costumes, seated on the terraces and balustrades of a sanctuary.
Seven formations (or groups) of the Tertiary strata have been distinguished in Mississippi.
The older formation of the Quaternary period is the Lafayette (also called "Orange-sand" or "stratified drift"), which immediately overlies all the Cretaceous groups except the prairies of the Selma chalk, and all the Tertiary except the Porters Creek and Vicksburg formations and parts of the Jackson.
The order is divided into two main groups based on the number of the stamens and stigmas.
On the east and south-east of Asia are several important groups of islands, the more southern of which link this continent to Australia, and to the islands of the Pacific. The Kurile Islands, the Japanese group, Luchu, Formosa and the Philippines, may be regarded as unquestionable outliers of Asia.
Of the islands in the Bay of Bengal the Nicobar and Andaman groups are alone worth notice.
The Laccadives and Maldives are groups of small coral islands, situated along the 73rd meridian, at no great distance from the Indian peninsula, on which they have a political dependency.
Here again we have an absence of all tropical forms, and a great development of groups characteristic of cold and temperate regions.
Linguistically they can be divided into several groups such as Turks, Mongols and Huns, but they were from time to time united into states representing more than one group, and their armies were recruited, like the Janissaries, from all the military races in the neighbourhood.
The position of this class, which has remained till the present day, is connected with the institution of caste, a division of the population into groups founded partly on racial distinctions.
They are disposed in two groups on either side, corresponding in the Polychaeta to the parapodia; the two bundles are commonly reduced among the earthworms to two pairs of setae or even to a single seta.
To this category will belong the oviducts in Teleostean fishes and probably the gonad ducts in several groups of invertebrates.
The remaining groups are harder to define, with the exception of the (3) Capitelliformia, which are mud-living worms of an "oligochaetous" appearance, and with some affinities to that order.
The prostomium has many long filaments which recall the gills of the Sabellids, &c. The nephridia are specialized into two series, as in the last-mentioned worms. (5) Spioniformia (including Chaetopterus, Spio, &c.) and (6) Scoleciformia (Arenicola, Chloraema, Sternaspis) are the remaining groups.
The epidermis contains numerous groups of sense cells; beneath the epidermis there is rarely (Kynotus) an extensive connective tissue dermis.
Berthelot, and many other chemists, from whose researches it results that glycerin is a trihydric alcohol indicated by the formula C 3 H 5 (OH) 3j the natural fats and oils, and the glycerides generally, being substances of the nature of compound esters formed from glycerin by the replacement of the hydrogen of the OH groups by the radicals of certain acids, called for that reason "fatty acids."
Various names are given to the different parts of the constituent ranges, or, perhaps more correctly, elongated groups of mountains.
Even in the rural districts, manorial records reveal the existence of a great variety of classes and groups of persons engaged in the performance of economic functions.
As in other Molluscan groups, we find a wide variation in the early process of the formation of the first embryonic cells, and their arrangement as a diblastula, dependent on the greater or less amount of food-yolk which is present in the egg-cell when it commences its embryonic changes.
The Heteropoda belong to the " pelagic fauna " occurring near the surface in the Mediterranean and great oceans in company with the Pteropoda, the Siphonophorous Hydrozoa, Salpae, Leptocephali, and other specially-modified transparent swimming representatives of various groups of the animal kingdom.
There are two great groups of schists, viz.
Differences of opinion with regard to the policies to be pursued by the new government gradually led to the formation of two well-defined political groups - the Federalists and the Democratic-Republicans - and Adams became recognized as one of the leaders, second only to Alexander Hamilton, of the former.
In various groups of the Hexapoda - aphids and some flesh-flies (Sarcophagi), for example - the egg undergoes development within the body of the mother, and the young insect is born in an active state; such insects are said to be " viviparous."
This by successive divisions forms a group of four to eight cells, which subsequently pass through the blastoderm, and dividing into two groups become symmetrically arranged and surrounded by the rudiments of the ovarian tubes.
For details, the reader may consult the special articles on the various orders and groups of insects.
Nevertheless, the constant increase of our knowledge of insect forms renders classification increasingly difficult, for gaps in the series become filled, and while the number of genera and families increases, the distinctions between these groups become dependent on characters that must seem trivial to the naturalist who is not a specialist.
None of the groups of existing Endopterygota have been traced with certainty farther back than the Mesozoic epoch, and all the numerous Palaeozoic insect-fossils seem to belong to forms that possessed only imperfect metamorphosis.
On reviewing the progress of ornithology since the end of the 18th century, the first thing that will strike us is the fact that general works, though still undertaken, have become proportionally fewer, while special works, whether relating to the ornithic portion of the fauna of any particular country, or limited to certain groups of birds - works to which the name of " Monograph " has become wholly restricted - have become far more numerous.
This is devoted to the very distinct and not nearly-allied groups of hornbills and of birds which for want of a better name we must call " Chatterers," and is illustrated, like those works of which a notice immediately follows, by coloured plates, done in what was then considered to be the highest style of art and by the best draughtsmen procurable.
The arrangement he subsequently adopted for them and for other groups is to be found in his Natiirliches System der Amphibien (pp. 77-128), published in 1830, and is too fanciful to require any further attention.
That no groups are natural which do not exhibit, or show an evident tendency to exhibit, such a circular series.
That there is a tendency in such groups as are placed at the opposite points of a circle of affinity ` to meet each other.'
That one of the five larger groups into which every natural circle is divided ` bears a resemblance to all the rest, or, more strictly speaking, consists of types which represent those of each of the four other groups, together with a type peculiar to itself.'
That the different ranks or degrees of circular groups exhibited in the animal kingdom are Nine k in number, each being involved within the other."
However, Nitzsch had not as yet seen his way to proposing any methodical arrangement of the various groups of birds, and it was not until some eighteen months later that a scheme of classification in the main anatomical was attempted.
It is not only a key to much of his later work - to nearly all indeed that was published in his lifetime - but in it are founded several definite groups (for example, Passerinae and Picariae) that subsequent experience has shown to be more or less natural; and it further serves as additional evidence of the breadth of his views, and his trust in the teachings of anatomy.
Two years later Nitzsch, who was indefatigable in his endeavour to discover the natural families of birds and had been pursuing a series of researches into their vascular system, published the result, at Halle in Saxony, in his Observationes de avium arteria carotide communi, in which is included a classification drawn up in accordance with the variation of structure which that important vessel presented in the several groups that he had opportunities of examining.
Consequently his labours had attained to a certain degree of completeness in this direction, and it may therefore be expedient here to name the different groups which he thus thought himself entitled to consider established.
To enable the reader to compare the several groups of Nitzsch with the families of L'Herminier, the numbers applied by the latter to his families are suffixed in square brackets to the names of the former; and, disregarding the order of sequence, which is here immaterial, the essential correspondence of the two systems is worthy of all attention, for it obviously means that these two investigators, starting from different points, must have been on the right track, when they so often coincided as to the limits of what they considered to be, and what we are now almost justified in calling, natural groups.'
This is the most usual fashion among the various groups of birds, including all the " aerial " forms excepting Passerinae, Macrochires and Picinae.
But it was now made to appear that the struthious birds in this respect resembled, not only the duck, but a great many other groups - waders, birds-of-prey, pigeons, passerines and perhaps all birds not gallinaceous - so that, according to Cuvier's view, the five points of ossification observed in the Gallinae, instead of exhibiting the normal process, exhibited one quite exceptional, and that in all other birds, so far as he had been enabled to investigate the matter, ossification of the sternum began at two points only, situated near the anterior upper margin of the side of the sternum, and gradually crept towards the keel, into which it presently extended; and, though he allowed the appearance of detached portions of calcareous matter at the base of the still cartilaginous keel in ducks at a certain age, he seemed to consider this an individual peculiarity.
At the same time he seems, according to the abstract of his memoir, to have made the somewhat contradictory assertion that sometimes there are more than three pieces in each series, and in certain groups of birds as many as six.
They extend to more than a score of natural groups of birds, and nearly each of them presents some peculiar characters.
The same variations are observable in the second or middle series, but its side-pieces are said to exist in all groups of birds without exception.
By way of examples of L'Herminier's observations, what he says of the two groups that had been the subject of Cuvier's and the elder Geoff roy's contest may be mentioned.
He was quite aware of the taxonomic value of the vocal organs of some groups of birds, presently to be especially mentioned, and he had himself ascertained the presence and absence of caeca in a not inconsiderable number of groups, drawing thence very justifiable inferences.
Moreover, as Professor Burmeister states in his preface, Nitzsch by no means regarded the natural sequence of groups as the highest problem of the systematist, but rather their correct limitation.
Again, the arrangement followed in the Pterylographie was of course based on pterylographical considerations, and we have its author's own word for it that he was persuaded that the limitation of natural groups could only be attained by the most assiduous research into the species of which they are composed from every point of view.
Further examination also revealed the fact 3 that in certain groups the number of " primaries," or quill-feathers growing from the manus or distal segment of the wing, formed another characteristic easy of observation.
In two of the other groups of which Professor Cabanis, especially treated - groups which had been hitherto more or less confounded with the Oscines - the number of primaries was invariably ten, and the outermost of them was comparatively large.
Yet this distinguished zoologist selects the sternum as furnishing the key to his primary groups or " Orders " of the class, adopting, as Merrem had done long before, the same two divisions Cartnatae and Ratitae, naming, however, the former Tropidosternii and the latter Homalosternii.
As it is, so much of them as we have are of considerable importance; for, in this unfortunately unfinished memoir, he describes in some detail the several differences which the sternum in a great many different groups of his Tropidosternii presents, and to some extent makes a methodical disposition of them accordingly.
Thus he separates the birds of prey into three great groups - (I) the ordinary Diurnal forms, including the Falconidae and Vulturidae of the systematist of his time; but distinguishing the American Vultures from those of the Old World; (2) Gypogeranus, the secretary-bird; and (3) the owls (q.v.).
That the eggs laid by birds should offer to some extent characters of utility to systematists is only to be expected, when it is considered that those from the same nest generally bear an extraordinary family likeness to one another, and also that in certain groups the essential peculiarities of the egg-shell are constantly and distinctively characteristic. Thus no one who has ever examined the egg of a duck or of a tinamou would ever be in danger of not referring another tinamou's egg or another duck's, that he might see, to its proper family, and so on with many others.
They could even discern dimly some generalized stock whence had descended whole groups that now differed strangely in habits and appearance - their discernment aided, may be, by some isolated form which yet retained undeniable traces of a primitive structure.
In this course of lectures he had already dwelt at some length on the insufficiency of the characters on which such groups as had hitherto been thought to be established were founded; but for the consideration of this part of his.
Huxley regarded the above scheme as nearly representing the affinities of the various Carinate groups - the great difficulty being to determine the relations to the rest of the Coccygomorphae, Psittacomorphae and Aegithognathae, which he indicated " only in the most doubtful and hypothetic fashion."
Almost simultaneously with this he expounded more particularly before the Zoological Society, in whose Proceedings (1868, pp. 2 94-3 1 9) his results were soon after published, the groups of which he believed the Alectoromorphae to be composed and the relations to them of some outlying forms usually regarded as Gallinaceous, the Turnicidae and Pteroclidae, as well as the singular hoactzin, for all three of which he had to institute new groups - the last forming the sole representative of his Heteromorphae.
From what has before been said of his works it may be gathered that, while professedly basing his systematic arrangement of the groups of birds on their external features, he had hitherto striven to make his schemes harmonize if possible with the dictates of internal structure as evinced by the science of anatomy, though he uniformly and persistently protested against the inside being better than the outside.
Nicholson in 1889, and had a considerable influence on later writers, especially in the arrangement of the smaller groups.
The Scutelliplantares include a much smaller number of forms, and, with the exception of the first " cohort " and a few groups of the fourth and fifth, all are peculiar to America.
The first of them, Accipitres, comprehending all the birds-of-prey, were separated into 4 " cohorts " in his original work, but these were reduced in his appendix to two - Nyctharpages or owls with 4 families divided into 2 series, and Hemeroharpages containing all the rest, and comprising io families (the last of which is the seriema, Dicholophus) divided into 2 groups as Rapaces and Saprophagi - the latter including the vultures.
Gibbons may be divided into two groups, the one represented by the siamang, Hylobates (Symphalangus) syndactylus, of Sumatra and the Malay Peninsula, and the other by a number of closely allied species.
Groups of dwellings, such as are still to be seen on some of the small canals at Burano, clustered together along the banks of the deeper channels which traverse the lagoon islands and give access to the tide.
The earliest churches were built with cemeteries for the dead; and thus we find the nucleus of the city of Venice, little isolated groups of dwellings each on its separate islet, scattered, as Cassiodorus 1 says, like sea-birds' nests over the face of the waters.
The Hohe Tauern contains the massifs of the Gross-Glockner (12,455 ft.), the Hochnarr (10,670 ft.) and the Ankogel (11,006 ft.), and is traversed by the saddles of the Hochthor and the Malnitzer Tauern, which separates these groups from one another.
The country south of the Drave is occupied by several groups of the southern limestone zone, namely the Carnic Alps, the Julian Alps, the Karawankes and the Steiner Alps.
Trap-door nests are made by spiders belonging to two widely different groups, namely the Lycosidae or wolf-spiders, to which the true tarantula belongs, and the Mygalomorphae, containing the species which construct the best-known types of this style of burrow.
Although there is no direct genetic affinity between the spiders of these two groups, an interesting parallelism in their habits may be traced.
Sagasta ultimately headed the most Conservative groups of the revolutionary politicians against Ruiz Zorrilla and the Radicals, and against the Federal Republic in 1873.
A coalition of generals and Conservatives turned Sagasta out in July 1890, and he only returned to the councils of the regency in December 1892, when the Conservative party split into two groups under Canovas and Silvela.
Generally, while there is a relative poverty of zoological groups, there is a great wealth of species within the group. Of gammarids, there are as many as 300 species, and those living at great depths (33 o to 380 fathoms) tend to assume abyssal characters similar to those displayed by the deep-sea fauna of the ocean.
The theories propounded may be divided into two groups, namely, those ascribing to petroleum an inorganic origin, and those which regard it as the result of the decomposition of organic matter.
Both Hetero- and Metane- mertini have been more exhaustively studied than the other two groups, the first, as was noticed above, being characterized by peculiar larval forms, the second developing without metamorphosis.
The middle toe was the largest, and the weight of the body was mainly supported on this and the two adjoining digits, which appear to have been encased in hoofs, thus foreshadowing the tridactyle type common in perissodactyle and certain extinct groups of ungulates.
The earliest settlement on the Acropolis was doubtless soon increased by groups of dwellings at its base, inhabited by the dependents of the princes who ruled in the stronghold.
It had already been understood that the various genera of the Ratitae were the representatives of so many different groups, each of which was at least equivalent to ordinal rank, and that therefore, if the Ratitae were still to be considered a natural group, this common ancestry must be referred to a remote geological epoch.
Although loss of flight (correlated with more or less reduction of the wings and the sternal keel, and often compensated by stronger hind limbs) has occurred, and is still taking place in various groups of birds, it is quite impossible that a new Ratite can still come into existence, because the necessary primitive substratum, whence arose the true Ratitae, is no longer available.
The fundamental chemical classification of matter, on the other hand, recognizes two groups of substances, namely, elements, which are substances not admitting of analysis into other substances, and compounds, which do admit of analysis into simpler substances and also of synthesis from simpler substances.
Groups of two or more atoms like SO 2 and OH, which are capable of playing the part of elementary atoms (that is to say, which can be transferred from compound to compound), are termed compound radicals, the elementary atoms being simple radicals.
Cleve proposed to divide the " rare earth " metals into two groups, (1) " perfectly characterized "; (2) " not yet thoroughly characterized."
Notwithstanding the inconsistency of his allocation of substances to the different groups (for instance, acetic acid was placed in the vegetable class, while the acetates and the products of their dry distillation, acetone, &c., were placed in the mineral class), this classification came into favour.
This description, although not absolutely comprehensive, serves as a convenient starting-point for a preliminary classification, since a great number of substances, including the most important, are directly referable to hydrocarbons, being formed by replacing one or more hydrogen atoms by other atoms or groups.
In fact, the analogy between the alkyl groups and metallic elements forms a convenient basis from which to consider many derivatives.
The ringed structure of benzene, C 6 H 61 was first suggested in 1865 by August Kekule, who represented the molecule by six CH groups placed at the six angles of a regular hexagon, the sides of which denoted the valencies saturated by adjacent carbon atoms, the fourth valencies of each carbon atom being represented as saturated along alternate sides.
The introduction of hydroxyl groups into the benzene nucleus gives rise to compounds generically named phenols, which, although resembling the aliphatic alcohols in their origin, differ from these substances in their increased chemical activity and acid nature.
Moreover, while methylamine, dimethylamine, and trimethylamine increase in basicity corresponding to the introduction of successive methyl groups, phenylamine or aniline, diphenylamine, and triphenylamine are in decreasing order of basicity, the salts of diphenylamine being decomposed by water.
Di-derivatives x x x p v as $ v as s Here we have assumed the substituent groups to be alike; when they are unlike, a greater number of isomers is possible.
In the case of tetra-substituted compounds, thirty isomers are possible when all the groups are different.
These three acids yield on heating phenol, identical with the substance started with, and since in the three oxybenzoic acids the hydroxyl groups must occupy positions other than I, it follows that four hydrogen atoms are equal in value.
Hence the positions occupied by the nitro groups in the two different nitrobrombenzoic acids must be symmetrical with respect to the carboxyl group. In 1879, Hubner (Ann., 1 95, p. 4) proved the equivalence of the second pair, viz.
By eliminating the hydroxy groups in these acids the same nitrobenzoic acid is obtained, which yields on reduction an aminobenzoic acid different from the starting-out acid.
Intermolecular transformations-migrations of substituent groups from one carbon atom to anotherare of fairly common occurrence among oxy compounds at elevated temperatures.
A larger and more important series of condensations may be grouped together as resulting from the elimination of the elements of water between carbonyl (CO) and methylene (CH 2) groups.
Bamberger (a strong supporter of the centric formula), have shown that the nature of the substituent groups influences the distribution of the fourth valencies; therefore it may be con-?
The proof of this statement rests on the fact that if the hydrogen atoms were not co-planar, then substitution derivatives (the substituting groups not containing asymmetric carbon atoms) should exist in enantiomorphic forms, differing in crystal form and in their action on polarized light; such optical antipodes have, however, not yet been separated.
It is remarkable that sulphur can replace two methine or CH groups with the production of compounds greatly resembling the original one.
Similarly, two or more methine groups may be replaced by the same number of nitrogen atoms with the formation of rings of considerable stability.
The three primary members are furfurane, thiophene and pyrrol, each of which contains four methine or CH groups, and an oxygen, sulphur and imido (NH) member respectively; a series of compounds containing selenium is also known.
Bergman laid the foundations of systematic qualitative analysis, and devised methods by which the metals may be separated into groups according to their behaviour with certain reagents.
The procedure for the detection of metals in solution consists of first separating them into groups and then examining each group separately.
The introduction of negative groups into a molecule alters the boiling-point according to the number of negative groups already present.
The principal chromophores are the azo, -N = N -, azoxy, = N 2 O, nitro, - N02, nitroso, - NO, and carbonyl, = CO, groups.
The nitro group has a very important action mainly on account of the readiness with which it can be introduced into the molecule, but its effect is much less than that of the azo group. The colour produced is generally yellow, which, in accordance with a general rule, is intensified with an increase in the number of groups; compare, for example, mono-, diand tri-nitrobenzene.
The carbonyl group by itself does not produce colour, but when two adjacent groups occur in the molecule, as for example in the a-diketones (such as di-acetyl and benzil), a yellow colour is produced.
The amino group is more powerful than the hydroxyl, and the substituted amino group more powerful still; the repeated substitution of hydroxyl groups sometimes causes an intensification and sometimes a diminution of colour.
Auxochromic groups generally aid one another, i.e.
The chromophoric groups are rarely strongly acid or basic; on the other hand, the auxochromes are strongly acid or basic and form salts very readily.
Notable differences attend the neutralization of the chromophoric and auxochromic groups.
Kauffmann (Ber., 1900, 33, p. 1 73 1; 1904, 35, p. 2 94; 1905, 3 8, p. 7 8 9; Ann., 1906, 344, p. 30) suggested that the property is due to the presence of at least two groups.
The measure of the loss of symmetry associated with the introduction of alkyl groups depends upon the relative magnitudes of the substituent group and the rest of the molecule; and the larger the molecule, the less would be the morphotropic effect of any particular substituent.
Other substituent groups exercise morphotropic effects similar to those exhibited by the alkyl radicles; investigations have been made on halogen-, hydroxy-, and nitro-derivatives of benzene and substituted benzenes.
The nitro group behaves very similarly to the hydroxyl group. The effect of varying the position of the nitro group in the molecule is well marked, and conclusions may be drawn as to the orientation of the groups from a knowledge of the crystal form; a change in the symmetry of the chemical molecule being often attended by a loss in the symmetry of the crystal.
It has been shown that certain elements and groups exercise morphotropic effects when substituted in a compound; it may happen that the effects due to two or more groups are nearly equivalent, and consequently the resulting crystal forms are nearly identical.
Other isomorphously related elements and groups were soon perceived, and it has been shown that elements so related are also related chemically.
German literature tells of several literary schools, or groups of writers animated by the same ideas, and working in the spirit of the same principles and by the same poetic methods.
The city is built upon the lower slope of the Serra do Ouro Preto, a spur of the Espinhago, deeply cut by ravines and divided into a number of irregular hills, up which the narrow, crooked streets are built and upon which groups of low, old-fashioned houses form each a separate nucleus.
In the course of time the centres of radiation of all these groups had imposed upon them ornate rose dei venti, or windroses, such as may still be seen upon our compass-cards.
Quakerism was preached in Scotland; very soon after its rise in England; but in the north and south of Scotland there existed, independently of and before this, preaching, groups of persons who were dissatisfied with the national form of worship and who met together in silence fordevotion.
Their colour varies from the Arab hue to black, and curiously enough the most regular features are to be found among the darkest groups.
Around the foot of the obelisk (besides an heroic statue of Lincoln) are four groups of figures in bronze, symbolizing the army and navy of the United States.
Under him were the several groups employed in the different branches of the exploitation and the care of the cattle and flocks, as well as those who kept or prepared the food, clothing and tools of the whole staff and those who attended on the master in the various species of rural sports.
The birds of the genus Leucosticte seem to be more terrestrial in their habit than those of Linota, perhaps from their having been chiefly observed where trees are scarce; but it is possible that the mutual relationship of the two groups is more apparent than real.
In the neighbourhood are the cave of Drach, containing several underground lakes, and the caves of Arta, one of the largest and finest groups of stalactite caverns in western Europe.
The distance from Dennis Head in North Ronaldshay of the Orkneys to Sumburgh Head in Shetland is 50 m., but Fair Isle, which belongs to Shetland, lies midway between the groups.
The tombs in some instances form subterranean groups more analogous to the general idea of a catacomb.
There are four functional toes in front and three behind; while the calcaneum, unlike that of the other three groups, articulates with the fibula.
Here the family is divided into two groups Rhinocerotinae and Elasmotheriinae, the latter including only Elasmotherium, and the former all the rest.
As just indicated there are three distinctively mountainous districts, various minor groups lying outside these.
It comprehends a number of independent groups.
Alone, or in groups, or in long aisles, towering above the plantations or its fellow trees of the forest, its beautiful crest dominates every landscape.
From early in the 19th century there had always been separatists, reformists and repressionists in the island, but they were individuals rather than groups.
For the subjects of this general heading see the articles ALGEBRA, UNIVERSAL; GROUPS, THEORY OF; INFINITESIMAL CALCULUS; NUMBER; QUATERNIONS; VECTOR ANALYSIS.
For the subjects of this heading see the articles DIFFERENTIAL EQUATIONS; FOURIER'S SERIES; CONTINUED FRACTIONS; FUNCTION; FUNCTION OF REAL VARIABLES; FUNCTION COMPLEX; GROUPS, THEORY OF; INFINITESIMAL CALCULUS; MAXIMA AND MINIMA; SERIES; SPHERICAL HARMONICS; TRIGONOMETRY; VARIATIONS, CALCULUS OF.
Also such ideas as those of invariants, groups and of form, have modified the entire science.
Since that time various other concessions have been granted to French and German financial groups, principally the Imperial Ottoman Bank group of Paris and the Deutsche Bank group of Berlin.
The tables on p. 440 show the respective lengths of the various Ottoman railways open and worked at the end of 1908 and the amount of kilometric guarantees which they carried - and the lengths, &c., of railways worked by the various companies according to the nationality of the concessionaire groups.
These four groups, however, were of unequal importance, and thanks to this arrangement the English, although weakest in point of numbers, were able to exercise the same influence in the council as if they had formed a fourth of the voters.
The arrival of the Spaniards at Constance necessitating the formation of a fifth nation, Pierre d'Ailly availed himself of the opportunity to ask either that the English nation might be merged in the German, or that each great nation might be allowed to divide itself into little groups each equivalent to the English nation.
It was therefore decided that with the cardinals each nation should associate six delegates, and that the successful candidate should be required to poll two-thirds of the suffrages, not only in the Sacred College, but also in each of these five groups.
In general terms the peach may be said to be a medium-sized tree, with lanceolate, stipulate leaves, borne on long, slender, relatively unbranched shoots, and with the flowers arranged singly, or in groups of two or more, at intervals along the shoots of the previous year's growth.
The family has very sharply defined characters, which separate its members at once from all other neuropterous (or pseudo-neuropterous) groups.
The albumoids include, according to Cohnheim, substances which possess certain properties in common, but differ from the preceding groups.
The possibility must be conceded that there were several arks in the course of Hebrew history and that separate tribes or groups of tribes had their own sacred object.
Constant cells may be divided into two groups, according as their action is chemical (as in the bichromate cell, where the hydrogen is converted into water by an oxidizing agent placed in a porous pot round the carbon plate) or electrochemical (as in Daniell's cell, where a copper plate is surrounded by a solution of copper sulphate, and the hydrogen, instead of being liberated, replaces copper, which is deposited on the plate from the solution).
It will be seen that they may be divided into two groups - alkali-micas (potash-mica, &c.) and ferromagnesian micas - which correspond roughly with the division into light and dark micas.
Clarke (1889-1893) supposes them to be substitution derivatives of normal aluminium orthosilicate A14(S104)3, in which part of the aluminium is replaced by alkalis, magnesium, iron and the univalent groups (MgF), (A1F2),(AlO), (MgOH); an excess of silica is explained by the isomorphous replacement of H 4 SiO 4 by the acid H4S130s.
In a later scheme based on our increased knowledge of fossil forms, the Brachiopoda are divided into four primary groups (orders).
Many more modifications are observable in different groups of which the great family Terebratulidae is composed.
I t may, however, be pointed out that Brachiopods seem to belong to that class of animal which commences life as a larva with three segments, and that tri-segmented larvae have been found now in several of the larger groups.
Livingston and Aaron Burr; and such Federalist control as there was from time to time after 1799 depended upon coalition with one or other of these groups.
Here they constituted themselves a free confederacy of many distinct tribal groups, each preserving the traditional customs, religious rites and even the very names of their original villages.
This arose from the study by Felix Klein and Sophus Lie of a new theory of groups of substitutions; it was shown that there exists an invariant theory connected with every group of linear substitutions.
The invariant theory then existing was classified by them as appertaining to " finite continuous groups."
Other " Galois " groups were defined whose substitution coefficients have fixed numerical values, and are particularly associated with the theory of equations.
Arithmetical groups, connected with the theory of quadratic forms and other branches of the theory of numbers, which are termed "discontinuous," and infinite groups connected with differential forms and equations, came into existence, and also particular linear and higher transformations connected with analysis and geometry.
This region, now embraced in the departments of Lozere and Gard, stretches south to include the Aigoual and Esperou groups.
The second is Fechner's method; it consists of recording the changes in feeling-tone produced in a subject by bringing him in contact with a series of conditions, objects or stimuli graduated according to a scientific plan and presented singly in pairs or in groups.
Two groups of observations were recorded, one giving the induction in the inner coil and the other that in the outer coil.
The lateral eyes of Scorpio consist of groups of separate small lenses each with its ommatidium, but they do not form a continuous compound eye as in Limulus.
Leaving that question for consideration in connexion with the systematic statement of the characters of the various groups of Arachnida which follows on p. 475, it is well now to consider the following question, viz., seeing that Limulus and Scorpio are such highly developed and specialized forms, and that they seem to constitute as it were the first and second steps in the series of recognized Arachnida - what do we know, or what are we led to suppose with regard to the more primitive Arachnida from which the Eurypterines and Limulus and Scorpio have sprung ?
We have now to offer a classification of the Arachnida and to pass in review the larger groups, with a brief statement of their structural characteristics.
The members of this group, whilst resembling the lower Crustacea (as all lower groups of a branching genealogical tree must do), differ from them essentially in that the head exhibits only one prosthomere (in addition to the eye-bearing prosthomere) with palpiform appendages (as in all Arachnida) instead of two.
Pocock, assistant in the Natural History departments of the British Museum, for valuable assistance in the preparation of this article and for the classification and definition of the groups of Eu-arachnida here given.
Probably tracheae have developed independently by the same process in several groups of tracheate Arachnids.
Lateral eyes also may be present, arranged in lateral groups, and having a single or double cell-layer beneath the lens.
Apparently related to the Opiliones are two extinct groups, the Anthracomarti and Phalangiotarbi, which are not known to have survived the Carboniferous period.
Though radical enough, this Land Act was still not sufficient to satisfy the groups which came into political power on June 3 1921.
The author had at his disposal two distinct groups of legends about Mary.
One of these groups is certainly of non-Jewish origin, as it conceives Mary as living in the temple somewhat after the manner of a vestal virgin or a priestess of Isis.
To Neolithic man, still perhaps represented by some of the more light-coloured and more regularfeatured Polynesian groups, may therefore not unreasonably be attributed these astonishing remains, which assume so many different forms according to the nature of the locality, but seem generally so out of proportion with the present restricted areas on which they stand.
Miller's Squamata and Nuda (1832), are merely new names for de Blainville's Ornithoides and Ichthyoides, though Muller gave far better anatomical characters of the two groups than had previously been put forward.
With this monument as a basis, Franz Cumont has arranged the small Mithraic reliefs into two groups, one illustrating the legend of the origin of the gods, and the other the legend of Mithras.
Brazil has three groups of animals similar to the common rat - the Capromydae, Loncheridae and Psammoryctidae- the best known of which is the " tuco-tuco " (Ctenomys brasiliensis), a small burrowing animal of Rio Grande do Sul which excavates long subterranean galleries and lives on roots and bulbs.
Of this smallest of birds there are fifty-nine well-known species, divided into two groups, the Phaethorninae, which prefer the forest shade and live on insects, and the Trochilinae, which frequent open sunny places where flowers are to be found.
After six months of civil war peace was once more established, but there still remained some small rebel groups in Rio Grande do Sul.
The city gaol, a castellated structure on the black rock of Calton Hill, forms one of the most striking groups of buildings in the town.
At the west end of George Street, in the centre of Charlotte Square, stands the Albert Memorial, an equestrian statue of the prince consort, with groups at each of the four angles of the base.
Substitution takes place usually in the nucleus and only rarely in the side chain, and according to the conditions of the experiment and the nature of the compound acted upon, one or more nitro groups enter the molecule.
The nitro group in the aromatic series is bound very firmly in the molecule and is not readily exchanged for other groups.
The portion of Hungary situated on the right bank of the Danube is filled by the Alpine system, namely, the eastern outlying groups of the Alps.
These groups are the Leitha mountains, the Styrian highlands, the Lower Hungarian highlands, which are a continuation of the former, and the Bakony Forest.
The various races of Hungary are distributed either in compact ethnographical groups, in larger or smaller colonies surrounded by other nationalities, or-e.g.
But all round these, as far as the frontiers, the country is inhabited by the other races, which, as a rule, occupy it in large, compact and uniform ethnographical groups.
Within this broad division, however, have appeared from time to time political groups in bewildering variety, each adopting a party designation according to the exigencies of the moment, but each basing its programme on one or other of the theoretical foundations above mentioned.
In the modern drama three great and clearly differentiated groups may be distinguished.