Pair Sentence Examples

Carmen made a ball out of a pair of socks.

You two make a fine pair, you know that?

I saw a pair on your car out there.

Bianca put on a pair of jeans and a T-shirt.

Molly smiled and the pair and dog left.

Slipping into a pair of tennis shoes, she headed for the kitchen.

She woke to bright sunlight shining through her window and jumped from the bed, tugging on a pair of shorts and a blouse.

They gave me a pair of her "wings," which I keep still.

We're a good pair.

You know that pair of women's gloves?

The female dealer was in her bra and a soaked pair of pants.

Dean wanted to question Edith further but she rose, with Effie following, her arm on Edith's elbow and the pair returned upstairs.

Bordeaux studied the dust through a pair of field glasses.

The drivingwheels are coupled to a pair of trailing wheels.

Associated with the lateral blood-vessels are the single pair of nephridia.

Fred finished his breakfast in a rush and hauled out the pair of his garage-sale skis.

The four sepals are arranged symmetrically, an outer median and an inner lateral pair.

There should also be only a single coelom, or a pair of lateral coelomic cavities.

As the most developed pair in birds they are com monly, although wrongly, called the hyoid horns.

The head of an ant carries a pair of elbowed feelers, each consisting of a minute basal and an elongate second segment, forming the stalk or "scape," while from eight to eleven short segments make up the terminal "flagellum."

D, Optical section of a branch of organs are present to the number of a single pair per somite, and are commonly present in the majority of the segments of the body, failing often among the Oligochaeta in a varying number of the anterior segments.

Frequently reduced in number of pairs; rarely (Capitellidae) more than one pair per segment.

It is held, however, that these are a pair of parapodia which have shifted forwards.

The same arrangement is found in some other Polychaetes; for instance, in Sabellaria there is a single pair of large anterior nephridia, which open by a common pore, followed after an interval by large-funnelled and short nephridia.

The spermathecae are usually paired structures, one pair to each of the segments where they occur.

The intestine has a pair of caeca or two or three pairs (but all lie in one segment) in the genus Pheretima and in one species of Rhinodrilus.

In Benhamia caecifera and at least one other earthworm there are numerous caeca, one pair to each segment.

The nervous system is embedded in the epidermis, and the pairs of ganglia are separated as in Serpula, &c.; each pair has a longish commissure between its two ganglia.

There are no setae and apparently only two pairs of nephridia, of which the anterior pair open commonly by a common pore on the third segment after the head, whose segments have not been accurately enumerated.

The intervening segments contain the genitalia, which are on the Oligochaeta plan in that the gonads are independent of their ducts and that there are special spermathecae, one pair.

The male ducts are either one pair or two pairs, which open by a common and complicated efferent terminal apparatus furnished with a protrusible penis.

In Pontobdella and Branchellion the nephridia form a network extending from segment to segment, but there is only one pair of funnels in each segment.

The testes are more numerous than the ovaries, of which latter there are never more than one pair.

An interesting member of this constellation is a-Capricorni, a pair of stars of 3rd and 4th magnitudes, each of which has a companion of the 9th magnitude.

The head bears only one pair of tentacles.

Spengel has, however, in a most ingenious way shown that these bodies are the representatives of the typical pair of ctenidia, here reduced to a mere rudiment.

The head is seen in front resting on the foot and carrying a median non-retractile snout or rostrum, and a pair of cephalic tentacles at the base of each of which is an eye.

It carries two pairs of cephalic tentacles and a pair of sessile eyes.

Laterally the foot gives rise to a pair of mobile fleshy lobes, the parapodia (ep), which can be thrown up so as to cover in the dorsal surface of the animal.

Our figure of the nervous system of Aplysia does not give the small pair of buccal ganglia which are, as in all glossophorous Molluscs, present upon the nerves passing from the cerebral region to the odontophore.

They are all pelagic, the foot being entirely transformed into a pair of anterior fins; eyes are absent, and the nerve centres are concentrated on the ven tral side of the oesophagus.

Body elongated; visceral mass marked off from foot posteriorly; dorsal appendages absent, or reduced to a single pair; spicules in the integument.

Never more than one pair of tentacles, and these are absent in Alderia and some species of Limapontia.

Karl Semper has shown that these slugs have, in addition to the usual pair of cephalic eyes, a number of eyes developed upon the dorsal integument.

Pulmonata with two pairs of tentacles, except Janellidae and Vertigo; these tentacles are invaginable, and the eyes are borne on the summits of the posterior pair.

The god was probably son and mate of the goddess, and the divine pair represented the genius of Reproductive Fertility in its relations with humanity.

At the same time he enjoined the pair to marry and people the world.

The Sidra Rabbet knows of three total destructions of the human race by fire and water, pestilence and sword, a single pair alone surviving in each case.

The thorax is composed of three segments; each bears a pair of jointed legs, and in the vast majority of insects the two hindmost bear each a pair of wings.

As previously mentioned, a pair of minute jaws - the maxillulae- are present in the lowest order of insects, between the mandibles and the first maxillae.

The second pair of maxillae are more or less completely fused together to form what is known as the labium or " lower lip."

In specialized biting insects, such as beetles (Coleo C ptera), the labium tends to become a hard transverse plate bearing the pair of palps, a median structure - known as the ligula - formed of the conjoined laciniae, and a pair of small rounded processes - the reduced galeae - often called the " paraglossae," a term better avoided since it has been applied also to the maxillulae of Aptera, entirety different structures.

It does not appear to represent a pair of appendages, but the maxillulae of the Aptera become closely associated with it.

Each segment of the thorax carries a pair of legs.

Most insects possess a pair of compound eyes, and many have, in addition, three simple eyes or ocelli on the vertex.

The labrum and clypeus are developed as a single prolongation of the oral piece, not as a pair of appendages.

The antennal segment apparently entirely disappears, with the exception of a pair of appendages it bears; these become the antennae; it is possible that the original segment, or some part of it, may even become a portion of the actual antennae.

Great difference of opinion exists as to the hypopharynx, which has even been thought to represent a distinct segment, or the pair of appendages of a distinct segment.

They are developed on the ventral surface of the body and are six in number, one pair arising from the eighth ventral plate and two pairs from the ninth.

In some embryos there is but a single pair of these rudiments (or vestiges) situate on the first abdominal segment, and in some cases they become invaginations of a glandular nature.

The continuous layer of cells from which the nervous system is developed undergoes a segmentation analogous with that we have described as occurring in the ventral plate; there is thus formed a pair of contiguous ganglia for each segment of the body, but there is no ganglion for the telson.

In Orthoptera, Heymons has demonstrated the existence of eleven pairs, the terminal pair becoming, however, soon united with the tenth.

These glands are represented externally by a special plate, the cribellum, which lies in front of the ordinary spinning mamillae, and by a comb of short bristles, the calamistrum, placed in the penultimate segment of the left of the last pair.

The sexes then pair and perish soon after the female has constructed her cocoon.

All spiders possess a pair of poison-glands, one in each of the chelicerae or mandibles and opening by means of a duct at the tip of the fang.

The brain-lobes are generally four in number, a ventral and a dorsal pair, respectively united together by the above-mentioned commissures, and moreover anteriorly interfusing with each other, right and left.

These posterior brain-lobes, which in all Heteronemertines are in direct continuity of tissue with the upper pair of principal lobes, cease to have this intimate connexion in the Metanemertini; and, although still constituted of (I) a ciliated duct, opening out externally, (2) nervous tissue surrounding it, and (3) histological elements distinctly different from the nervous, and most probably directly derived from the oesophageal outgrowths, they are nevertheless here no longer constantly situated behind the upper brain-lobes and directly connected with them, but are found sometimes behind, sometimes beside and sometimes before the brain-lobes.

The more highly organized species have often very numerous eyes (Amphiporus, Drepanophorus), which are provided with a spherical refracting anterior portion, with a cellular " vitreous body," with a layer of delicate radially arranged rods, with an outer sheath of dark pigment, and with a separate nerve-twig each, springing from a common or double pair of branches which leave the brain as n.

Let -I- B, - B, be two smaller trunnions which project out from the sides of the two strips connecting together a pair of rings CC. The rings and the connecting strips constitute the circuit which is to be rendered movable.

Each instrument is accompanied by a pair of weights and by a square root table, so that the product of the square root of the number corresponding to the position of the sliding weight and the ascertained constant for each weight, gives at once the value of the current in amperes.

In front of the pylon Rameses set up colossi and a pair of obelisks (one of which was taken to Paris in 1831 and re-erected in the Place de la Concorde).

In the female the ovary is a large unpaired organ from the anterior end of which arise two oviducts, and connected with the latter are a pair of large so-called copulatory pouches, which perhaps act as receptacula seminis.

The orifice leads into a large pouch lodging a pair of very long penes, which are coiled up when not in use.

Also communicating with this pouch is a pair of long slender flagelliform tubes, of which the function is unknown.

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.

Therefore there must be another pair of hydrogen atoms, other than 2 and 6, which are symmetrical with respect to 1.

A doubly linked pair of atoms is denoted by the sign A with the index corresponding to the side; if there are two pairs of double links, then indices corresponding to both sides are employed.

Restricting ourselves to compounds resulting from the fusion of benzene rings, we have first to consider naphthalene, C10H8, which consists of two benzene rings having a pair of carbon atoms in common.

Again, the pyroxenes, RS103 (R=Fe, Mg, Mn, &c.), assume the forms (I) monoclinic, sometimes twinned so as to become pseudo-rhombic; (2) rhombic, resulting from the pseudo-rhombic structure of (I) becoming ultramicroscopic; and (3) triclinic, distinctly different from (I) and (2); (I) and (2) are polysymmetric modifications, while (3) and the pair (I) and (2) are polymorphs.

The feet are five-toed, and the third and fourth toes of the front pair armed with enormous claws adapted for digging.

Their plan is for the most part that of a house, with a door of entrance and passage leading into a central chamber or atrium, with others of smaller size opening from it, each having a stone-hewn bench or triclinium on three of its sides, on which the dead, frequently a pair of corpses side by side, were laid as if at a banquet.

The upper cheek-teeth are short-crowned and without cement, and show distinct traces of the primitive tubercles; the two outer columns form a more or less complete external wall, connected with the inner ones by a pair of nearly straight transverse crests; and the premolars are originally simpler than the molars.

The other upper premolars and molars all formed on the same plan and of nearly the same size, with four roots and quadrate crowns, rather wider transversely than from before backwards, each having four columns, connected by a pair of transverse ridges, anterior and posterior.

The first lower premolar compressed in front; the others composed of a single pair of transverse crests, with a small anterior and posterior basal ridge.

Finally, in the Oligocene Colodon the last three upper premolars are like the molars, and the first pair of lower incisors is lost.

As stated above, the lower molars have the crown formed by a pair of crescents; the last having no third lobe.

Possibly they belonged to the Amynodontidae, but they may have been related to the Upper Oligocene Diceratherium, in which the nasal bones formed a transverse pair; this genus being common to Europe and North America.

The ordinal number is the class whose sole member is the null relation - that is, the relation which never holds between any pair of entities.

But even this did not quite complete the distance, and the line was carried on for still another kilometre and there stopped, " with its pair of rails gauntly projecting from the permanent way " (Fraser, The Short Cut to India, 1909).

Mme de Stael was accused of extravagance, and latterly an amicable separation of goods had to be effected between the pair.

In accordance with this manner of feeding, the mouth is kept permanently open and prevented from collapsing by a pair of skeletal cornua belonging to a sustentacular apparatus (the nuchal skeleton), the body of which lies within the narrow neck of the proboscis; the latter is inserted into the collar and surrounded by the anterior free flap of this segment of the body.

Of these divisions of the coelom the first two communicate with the exterior by means of a pair of ciliated pore-canals placed at the posterior end of their respective segments.

Correlated with the presence of the genital pleurae there is a pair of vascular folds of the basement membrane proceeding from the dorsal wall of the gut in the postbranchial portion of the branchio-genital region, and from the dorsal angles made by the pleural folds with the body-wall in the pharyngeal region; they pass, in their most fully developed condition, to the free border of the genital pleurae.

If two solutions containing the salts AB and CD be mixed, double decomposition is found to occur, the salts AD and CB being formed till a certain part of the first pair of substances is transformed into an equivalent amount of the second pair.

The proportions between the four salts AB, CD, AD and CB, which exist finally in solution, are found to be the same whether we begin with the pair AB and CD or with the pair AD and CB.

The Shilka and the Argun, which form it, flow first towards the north-east along the windings of the lower terrace of the great plateau; from this the Amur descends, cutting through the Great Khingan and flowing down the terraces of the eastern versant towards the Pacific. A noteworthy feature of the principal Siberian rivers is that each is formed by the confluence of a pair of rivers.

In Rhynchonella, where there are two pairs of kidneys, the internal opening of the anterior pair is supported by the gastroparietal band and that of the posterior pair by the ileoparietal band.

The latter pair alone persists in all other genera.

The function of this pair of muscles is the closing of the valves.

The accessory divaricators are, according to the same authority, a pair of small muscles which have their ends attached to the ventral valve, one on each side of the median line, a little behind the united basis of the adductors, and again to the extreme point of the cardinal process.

Moreover, instead of having one pair of variables x i, x2 we may have several pairs yl, y2; z i, z2;...

As new axes of co-ordinates we may take any other pair of lines through the origin, and for the X, Y corresponding to x, y any new constant multiples of the sines of the angles which the line makes with the new axes.

Orthogonal System.-In particular, if we consider the transformation from one pair of rectangular axes to another pair of rectangular axes we obtain an orthogonal system which we will now briefly inquire into.

A magnet may be regarded as consisting of an infinite number of elementary magnets, each having a pair of poles and a definite magnetic moment.

For this reason a thin bar suspended at its centre of gravity between a pair of magnetic poles will, if paramagnetic, set itself along the line joining the poles, where the field is strongest, and if diamagnetic, transversely to the line.

Ewing (Magnetic Induction, § 194) has devised an arrangement in which two similar test bars are placed side by side; each bar is surrounded by a magnetizing coil, the two coils being connected to give opposite directions of magnetization, and each pair of ends is connected by a short massive block of soft iron having holes bored through it to fit the bars, which are clamped in position by set-screws.

The standard rod and the test specimen, which must be of the same dimensions, are placed side by side within two magnetizing coils, and each pair of adjacent ends is joined by a short rectangular block or " yoke " of soft iron.

On the surface of the carapace there are in both animals a pair of central eyes with simple lens and a pair of lateral eyetracts, which in Limulus consist of closely-aggregated simple eyes, forming a " compound" eye, whilst in Scorpio they present several AC separate small eyes.

The first pair of foliaceous appendages in each animal is the genital operculum; beneath it are found the openings of the genital ducts.

The second pair of mesosomatic appendages in Scorpio are known as the " pectens."

In the case of Scorpio this segment is indicated in the embryo by the presence of a pair of rudimentary appendages, carried by a well-marked somite.

But it is necessary to remember, in the light of recent discoveries, that the sixth prosomatic pair of appendages is carried on the seventh somite of the whole series, there being two prosthomeres or somites in front of the mouth, the first carrying the eyes, the second the chelicerae; also that the first mesosomatic or genital somite is not the seventh or even the eighth of the whole series of somites which have been historically present, 1 See the article Arthropoda for the use of the term " prosthomere."

The second has for its pair of appendages the small pair of limbs which in all living Arachnids is either chelate or retrovert (as in spiders), and is known as the chelicerae.

The cerebral mass is in Limulus more easily separated by dissection as a median lobe distinct from the laterally placed ganglia of the cheliceral somite than is the case in Scorpio, but the relations are practically the same in the two forms. Formerly it was supposed that in Limulus both the chelicerae and the next following pair of appendages were prosthomerous, as in Crustacea, but the dissections of Alphonse Milne-Edwards (6) demonstrated VI FIG.

A similar pair of coxal glands, lobate instead of ovoid in shape, was described by Lankester in Mygale, and it was also shown by him that the structures in Limulus called " brick-red glands " by Packard have the same structure and position as the coxal glands of Scorpio and Mygale.

In all the embryonic or permanent opening is on the coxa of the fifth pair of prosomatic limbs.

The latter open at the base of the fifth pair of limbs of the Crustacean, just as the coxal glands open on the coxal joint of the fifth pair of limbs of the Arachnid.

In Limulus small entosternites are found in each somite of the appendage-bearing mesosoma, and we find in Scorpio, in the only somite of the mesosoma which has a welldeveloped pair of appendages, that of the pectens, a small entosternite with ten pairs of muscles inserted into it.

The only point in which the gut of Limulus resembles that of Scorpio rather than that of any of the Crustacea, is in possessing more than a single pair of ducts or lateral outgrowths connected with ramified gastric glands or gastric caeca.

The Crustacea never have more than one pair.

Scorpio is here provided with a single or double pair of renal excretory tubes, which have been identified by earlier authors with the Malpighian tubes of the Hexapod and Myriapod insects.

It is not a pair of simple tubes, nor of dendriform tubes, but a closed network.

There is some reason to admit the existence of another more anterior pair of these muscles in Scorpio; this would make the number exactly correspond with the number in Limulus.

They differ from the Crustacea in that they have only a single pair of prae-oral appendages, the second pair being definitely developed as mandibles.

The fact that the single pair of prae-oral appendages of trilobites, known only as yet in one genus, is in that particular case a pair of uni-ramose antennae - does not render the association of trilobites and Arachnids improbable.

Although the prae-oral pair of appendages in the higher Arachnida is usually chelate, it is not always so; in spiders it is not so; nor in many Acari.

On the 1 A pair of round tubercles on the labrum (camerostome or hypostoma) of several species of Trilobites has been described and held to be a pair of eyes (22).

The single pair of palpiform appendages in front of the mouth has been found in one instance to be antenniform, whilst the numerous post-oral appendages in the same genus were bi-ramose.

These plates may fuse, and yet the somites to which they belong may remain distinct, and each have its pair of appendages well developed.

In the latter the single pair of antennae springing up from each side of the camerostome or hypostome or upper lip-lobe are seen.

The genital pores are situate at the base of the 7th pair of limbs, and may be repeated From Parker and Haswell's Text-book after Hoek.

In certain derivative forms constituting the family Pallenidae, however, the appendages of the 2nd pair are either rudimentary or atrophied altogether.

In the Hannoniidae, however, which resemble the Pycnogonidae in the absence of the 3rd pair in the female and of the 2nd pair in both sexes, the 1st pair are retained in both sexes.

The first pair of limbs is often chelate or prehensile, rarely antenniform; whilst the second, third and fourth may also be chelate, or may be simple palps or walking legs.

In the same and other leading forms a pair of much-coiled glandular tubes, the coxal glands (coelomocoels in origin), is found with a duct opening on the coxa of the fifth pair of appendages of the prosoma.

The alimentary canal is uncoiled and cylindrical, and gives rise laterally to large gastric glands, which are more than a single pair in number (two to six pairs), and may assume the form of simple caeca.

The mouth lying far back, so that the basal segments of all the prosomatic appendages, excepting those of the 1st pair, are capable of acting as masticatory organs.

The small first pair of appendages is concealed from view by the carapace.

Appendages of 1st pair.tri-segmented, chelate; of 2nd pair chelate, with their basal segments subserving mastication; of 3rd, 4th, 5th and 6th pairs similar in form and function, except that in recent and Carboniferous forms the basal segments of the 3rd and 4th are provided with sterno-coxal (maxillary) lobes, those of the 4th pair meeting in the middle line and underlying the mouth.

The meeting of the coxae of all the prosomatic limbs in front of the pentagonal sternum; the space for a genital operculum; the pair of pectens, and the absence of any evidence of pulmonary stigmata are noticeable in this specimen.

The Silurian scorpion Palaeophonus, differs, so far as obvious points are concerned, from a modern scorpion only in the thickness of its legs and in their terminating in strong spike-like joints, instead of being slight and provided with a pair of terminal claws.

The fifth pair of prosomatic appendages is used by these scorpions when burrowing, to kick back the sand as the burrow is excavated by the great chelae.

Appendages of 2nd pair with their basal segments united in the middle line and incapable of lateral movement; appendages of 3rd pair with only the apical segment many-jointed.

Appendages of 2nd pair folding in a horizontal plane, completely chelate, the claw immovably united to the sixth segment.

There is also a pair of narrow tergal sclerites interposed between the anterior and posterior shields.

Appendages of 2nd pair folding in a vertical plane, not chelate, the claw long and movable.

Between the bases of the sixth pair cf limbs and behind the prosomatic carapace is seen the tergite of the small prae-genital somite.

Appendages of 1st pair have two segments, as in Pedipalpi, but are furnished with poison gland, and are retroverts.

Appendages of 2nd pair not underlying the mouth, but freely movable and, except in primitive forms, furnished with a maxillary lobe; the rest of the limb like the legs, tipped with a single claw and quite unmodified (except in a').

In front of it the narrow waist is formed by the soft sternal area of the praegenital somite; 2, the sternite of the 2 second opisthosomatic somite covering the posterior pair of lung-sacs; and 4, the spinning appendages (limbs) of the opisthosoma; a, inner, b, outer ramus of the appendage; I I, sternite of the eleventh --

The " retrovert " or bent-back first pair of appendages is provided with a poison gland opening on the fang or terminal segment.

Appendages of 1st pair consisting of three segments, completely chelate, without poison gland; of 2nd pair slender, leg-like, tipped with three claws, the basal segment without sterno-coxal process taking no share in mastication, and widely separated from its fellow of the opposite side; 3rd, 4th, 5th and 6th appendages similar in form to the 2nd and to each other.

Proboscis free, not supported from below by either the prosternum or the basal segments of the appendages of the 2nd pair.

Remaining pairs of appendages with their basal segments immovably fixed to the sternal surface, similar in form, the posterior three pairs furnished with two claws supported on long stalks; the basal segments of the 6th pair bearing five pairs of tactile sensory organs or malleoli.

Third or hindermost plate of the prosoma beneath which the sixth pair of legs is articulated.

The proportionately enormous chelae (chelicerae) of the first pair of appendages are not provided with poison glands; their bite is not venomous.

Appendages of 2nd pair very large and completely chelate, their basal segments meeting in the middle line, as in the Uropygi, and provided in front with membranous lip-like processes underlying the proboscis.

Respiratory organs tracheal, opening by a pair of spiracles in the prosoma above the base of the fifth appendage on IV III I composed, at least in many cases, of eleven somites, the 1 1 th somite very small, often hidden within the loth.

Respiratory organs in the form of tracheal tubes opening by a pair of stigmata in the 2nd and 3rd somites of the opisthosoma.

Serrula on movable digit of appendages of 1st pair fixed throughout its length, and broader at its proximal than at its distal end; the immovable digit with an external process.

Appendages of 2nd pair, with their basal segments uniting in the middle line below the mouth, weakly chelate at apex.

Appendages of 3rd, 4th, 5th and 6th pairs similar in form; their basal segments in contact in the middle line and immovably welded, except those of the 3rd pair, which have been pushed aside so that the bases of the 2nd and 4th pairs are in contact with each other.

Intromittent organ of male placed at the distal end of the appendage of the 5th pair.

Respiratory organs tracheal, opening by a pair of stigmata situated immediately behind the basal segments of the 6th pair of appendages on what is probably the sternum of the 2nd opisthosomatic somite and also in some cases upon the 5th segment of the legs.

The carapace of the prosoma was unsegmented and often bore a pair of eyes.

Tracheae opening by a pair of stigmata situated above and behind the base of the 4th or 5th or 6th pair of appendages.

Tracheae, except in the aquatic species in which they are atrophied, opening by a pair of stigmata situated close to or above the base of the appendages of the 1st pair (mandibles).

The 1st pair of appendages both in this and in C are retracted.

If, for a twocompartment shaft, a pair of drums (or a single wide drum) be keyed to the engine shaft, with the ropes wound in opposite directions, the hoisting is " in balance," that is, the cages and cars counterbalance each other, so that the engine has to raise only the useful load of mineral, plus the rope.

A man-engine consists of two heavy wooden rods (like the rods of a Cornish pumping plant), placed parallel and close to each other in a special shaft compartment, and suspended at the surface from a pair of massive walking beams (or " bobs ").

In nearly all the other Pleistocene forms these teeth were subcylindrical in shape, with the summit of the crown (except sometimes in the first pair) forming a cup-like depression; enamel being in all cases absent.

The four suckers are here united to form two pairs or fused into a single pair.

Each cansists of an eversible hollow tentacle provided with hooklets and capable of introversion within a mem The excretory organs consist of flame-cells, richly convoluted canaliculi, and a pair of longitudinal canals leading to the exterior by one or more pores.

A rostellum and four phyllidia united to form a pair.

The weight of these implements necessitates some provision for turning them at the headlands, and this is supplied either by a bowl wheel, enabling the plough to be turned on one side, or by a pair of wheels cranked so that they can be raised by a lever when the plough is working.

It has been calculated that a single pair of guineapigs may prove the parent stock of a thousand individuals in a single year.

Apart from these characteristics, the most distinctive feature of earwigs is the presence at the end of the abdomen of a pair of pincers which are in reality modified appendages, known as cercopods, and represent the similar limbs of Japyx and the caudal feelers of Campodea and some other insects.

The larvae are active and voracious little grub-like creatures (known in the United States as "wrigglers"), with large heads and jaws provided with a pair of brushes, which sweep food-particles into the mouth.

The former consist of one pair or more of vesicular testes communicating by fine ducts with a vesicula seminalis.

Lastly the nervous system is well developed and consists of a pair of well-marked and interconnected ganglia placed near the anterior end and dorsal to the oesophagus.

The excretory system opens to the exterior by a pair of dorsal pores at the level of the pharynx.

If successful, the larva throws off its cilia and develops a dorsal papilla, a median ventral sucker and an additional pair of lateral suckers.

A pair of "eye-spots" develops immediately over the brain.

The weakest pair of concave lenses with which one can read clearly test types at a distance of 18 ft.

Young adults with slighter forms of hypermetropia need glasses only for near work; elderly people should have one pair of weak glasses for distant and another stronger pair for near vision.

The central nervous system (x) is highly developed, and in Loxosoma bears a pair o` eyes.

The principal differences are the complication of the ciliated band, the absence of the excretory organ, the great lateral compression of the body, the possession of a pair of shells protecting the sides, the presence of an organ known as the "pyriform organ," and the occurrence of a sucker in a position corresponding with the depression seen between (m) and (a) in fig.

In appearance tsetse are somewhat narrow-bodied flies, with a prominent proboscis, which projects horizontally in front of the head, and with the wings in the resting position closed flat one over the other like the blades of a pair of scissors.

They consented, however, to receive his wife, and the pair went on a visit to Montpellier.

The poison is secreted in modified upper labial glands, or in a pair of large glands which are the homologues of the parotid salivary glands of other animals.

Another variety has a red back, with pairs of black crossbars, the bands of each pair being separated by a narrow yellow space; sides brown, dotted with black; belly dark green, the outer portion of each ventral shield being yellow,.

Herpeton of Cambodia has a pair of long tentacles on the snout and is said to have a partly vegetable diet!

The phenomena which succeed each other are then very similar, whether A and B are two metals, such as lead and tin or silver and copper, or are a pair of fused salts, or are water and common salt.

In the case of this pair of metals, or indeed of any metallic alloy, we cannot see the crystals forming, nor can we easily filter them off and examine them apart from the liquid, although this has been done in a few cases.

In the latter case the larva crawls about the bottom of the water or up the stems of plants, with its thickly-chitinized head and legs protruding from the larger orifice, while it maintains a secure hold of the silk lining of the tube by means of a pair of strong hooks at the posterior end of its soft defenceless abdomen.

The same arrangement can be supplied to a pair of coaxial cylinders.

The typical insectan ovipositor with its three pairs of processes, one pair belonging to the eighth and two pairs to the ninth abdominal segment, can be distinguished in the female.

In the South Staffordshire and other Midland coalfields, where only shallow pits are required, and the coals are thick, a pair of pits may be sunk for a very few acres, while in the North of England, on the other hand, where sinking is expensive, an area of some thousands of acres may be commanded from the same number of pits.

Both incisors and canines are devoid of roots and grow throughout life, the canines, and in the typical species one pair of lower incisors, growing to an immense size.

Their centres s l, s2, are held respectively by the pieces A, B, which together form a sliding pair.

We progress by making explicit the oppositions contained in the fundamental synthesis, by uniting these opposites, analysing the new synthesis, and so on, until we reach an ultimate pair.

Such a mass of imaginary matter as we are now considering may be compared to a collection of heavy particles held in position relatively to one another by a system of light spiral springs, one spring being supposed to connect each pair of adjacent particles.

In certain species of mylodon the front pair of teeth in each jaw is placed some distance in front of the rest and has the crown surface obliquely bevelled by From Owen.

The body is elongated and furnished with four pairs of short, unjointed, stump-like legs, each terminated by a pair of claws.

The mouth, situated at the opposite end and armed with a pair of stylets, leads into an oesophagus, into which the ducts of a pair of so-called salivary glands open.

No organs of circulation or respiration are known; but the nervous system is well developed, and consists of a pair of ganglia corresponding with the limbs and connected by longitudinal commissural chords.

Anteriorly these chords embrace the oesophagus and unite with the cerebral mass which innervates the pair of eyes when present.

The sexes are not distinct, the sexual organs being represented by a pair of testes and a single ovary, which open together into the posterior end of the alimentary canal.

These last characteristics also separate them essentially from the Pycnogonida, some members of which resemble them to a certain extent in having only four pairs of limbs, no gnathites, no respiratory organs, a ganglionated ventral nervous system, and the abdomen reduced to a mere rudiment projecting between the last pair of legs.

The accidental use of a single name, America, for the pair of continents that has a greater extension from north to south than any other continuous land area of the globe, has had some recent justification, since the small body of geological opinion has turned in favour of the theory of the tetrahedral deformation of the earth's crust as affording explanation of the grouping of continents and oceans.

As discovery revealed the existence of another vast domain to the north, the name spread to the whole of the pair of continents by customary use, in spite of the protests of the Spaniards, by whom it was not officially used of North America till the 18th century.

With the palla, or impala(A epyceros melampus), we reach an exclusively African genus, characterized by the lyrate horns of the bucks, the absence of lateral hoofs, and the presence of a pair of glands with black tufts of hair on the hind-feet.

In the duikers themselves the single pair of horns is set in the midst of a tuft of long hairs, and the face-gland opens in a long naked line on the side of the face above the muzzle.

Very severe punishments were suggested for the clandestine lover, but the emperor rewarded the devotion of the pair by consenting to their marriage.

In the general solar spectrum this element is represented by a large number of lines, but in the spectrum of the prominences and chromosphere one pair only can be detected.

The rectangle, for instance, has so far been regarded as a plane figure bounded by one pair of parallel straight lines and another pair at right angles to them, so that the conception of " rectangularity " has had reference to boundary rather than to content; analytically, the rectangle must be regarded as the figure generated by an ordinate of constant length moving parallel to itself with one extremity on a straight line perpendicular to it.

A briquette may therefore be defined as a solid figure bounded by a pair of parallel planes, another pair of parallel planes at right angles to these, a base at right angles to these four planes (and therefore rectangular), and a top which is a surface of any form, but such that every ordinate from the base cuts it in one point and one point only.

In the case of the briquette the position of the foot of the ordinate u is expressed by co-ordinates x, y, referred to a pair of axes parallel to a pair of sides of the base of the briquette.

A plane parallel to either pair of sides of the briquette is a " principal plane."

Suppose that we take a pair of parallel planes, such that the solid extends from one to the other of these planes.

Then we can take the strips in pairs, and treat each pair as a parabolic trapezette.

An early improvement was the introduction of a tool resembling a pair of tongs, the two dies being placed one at the extremity of each leg.

Recently the practice of driving rolls by electricity has been growing, the advantage being that each pair of rolls can be driven independently without the intervention of cumbrous shafting.

The coins are then gripped by a pair of india-rubber driving wheels, which force them past the rim of a thin disk with notches in its edge to fit the coins.

An ohmmeter in one form consists of two pairs of coils, one pair called the series coil and the other called the shunt coil.

Kb(30s, a cube), in geometry, a solid bounded by six equal squares, so placed that the angle between any pair of adjacent faces is a right angle.

The technical name, Notonecta, meaning "back-swimmer," alludes to the habit of the insect of swimming upside down, the body being propelled through the water by powerful strokes of the hind legs, which are fringed with hair and, when at rest, are extended laterally like a pair of sculls in a boat.

He married in 1793 Mlle Deloche, daughter of a former avocat au conseil; the young pair were greatly straitened in means in consequence of the depreciation of the assignats.

But when the pasteboard is removed, then there is at the ear opposition of phase between the first and the second pair of waves, and consequently a minimum of sound.

But the real meaning is not slight; the sexual distinction has been discovered, and a new sense of shame sends the human pair into the thickest shades, when Yahweh-Elohim walks abroad.

The sentences which he passes are decisive, not only for the human pair and the serpent, but for their respective races.

Elsewhere eating the fruit of the "tree of wisdom" is given as the cause of the expulsion of the human pair.

In the former the main supporting member or members may be an arch ring or arched ribs, suspension chains or ropes, or a pair of girders, beams or trusses.

The chains of each pair were connected by bracing so that they formed a stiff inverted arch resisting deformation in its place.

There are fifteen main transverse girders to each shore span, with nine longitudinal girders between each pair.

It consists of a pair of tubular girders with solid or plate sides stiffened by angle irons, one line of rails passing through each tube.

In a state of nature canaries pair, but under domestication the male bird has been rendered polygamous, being often put with four or five females; still he is said to show a distinct preference for the female with which he was first mated.

Two more children had been born to the royal pair, Prince Leopold (duke of Albany) on the 7th of April 1853, and on the 14th of April 1857 their last child, the princess Beatrice (Princess Henry of Battenberg), bringing the royal family up to nine - four sons and five daughters.

The Meping and Mewang on the W., rising among the loftiest ranges, are rapid and navigable only for small boats, while the Meyom and Menam, the eastern pair, afford passage for large boats at all seasons and for deep draught river-steamers during the flood-time.

They pair on land, the male clasping the female at the arms, and the impregnation is internal.

After the assassination of Buckingham in 1628 the barrier between the married pair was broken down, and the bond of affection which from that moment united them was never loosened.

In other varieties of Patience the object is to make pairs, which are then discarded, the game being brought to a successful conclusion when all the cards have been paired; or to pair cards which will together make certain numbers, and then discard as before.

Whilst the marriage festivities were being celebrated the judgment of Heaven descended on the guilty pair; fire came from below; the water became hot and the sheikh and his sister were turned into stone.

One terminal of the galvanometer can then be shifted to the junction 6 7 g between any pair of consecutive coils and the slider shifted to any point on the potentiometer wire.

The heart has a pair of venous ostia, often blending into one, and an anterior arterial aorta.

Considering the imprisonment of the ostracod body within the valves, it is more surprising that the Asteropidae and Cypridinidae should have a pair of compound and sometimes large eyes, in addition to the e median organ at the base of I the " frontal tentacle," than 6 that other members of the group should be limited to P that median organ of sight, or have no eyes at all.

The first legs, meaning thereby the sixth pair of appendages, are generally pediform and locomotive, but sometimes unjointed, acting as a kind of brushes to cleanse the furca, while in the Polycopidae they are entirely wanting.

The " brush-formed " organs of the Podocopa are medially placed, and, in spite of their sometimes forward situation, Miller believes among other possibilities that they and the penis in the Cypridinidae may be alike remnants of a third pair of legs, not homologous with the penis of other Ostracoda (Podocopa included).

Giesbrecht and Hansen have shown that the mouth-organs consist of mandibles, first and second maxillae and maxillipeds; and Claus himself relinquished his long-maintained hypothesis that the last two pairs were the separated exopods and endopods of a single pair of appendages.

In the latter case the middle segment almost always carries with it to the hind-body a pair of rudimentary limbs, whence the term Podoplea, meaning species that have a pleon with feet.

In this tribe the males have both antennae of the first pair as sensory organs.

Here the males have one or the other of the first pair of antennae modified into a grasping organ for holding the female.

The pair thus handfasted were, in accordance with Scotch law, entitled to live together for a year and a day.

Pseudopus, the glass-snake, from Morocco and the Balkan peninsula to Burma and Fokien; also in the U.S.A., with the limbs reduced to a pair of tiny spikes near the vent, and a lateral fold along the snake-like body.

The vermiform body is covered with cycloid imbricating scales, devoid of osteoderms. Limbs and even their arches are absent, excepting a pair of flaps which represent the hind-limbs in the males.

Forelimbs absent; hind-limbs transformed into a pair of scale-covered flaps.

In 1736 there were under 10,000 inhabitants in the former city; in 1760 when Horace Walpole passed through it, buying for two guineas a pair of candlesticks of the local plate, which he thought "quite pretty," and pronouncing it to be "one of the foulest towns in England," there were two-and-twenty thousand who remitted eleven thousand pounds a week to London.

One of the causes of these sudden advances is undoubtedly to be found in the acquisition of a new and extremely useful character., Thus the perfect jaw and the perfect pair of lateral fins when first acquired among the fishes favoured a very rapid and for a time unchecked development.

Among the Barbelognostics (Irenaeus 29.3), the Primal Man (Adamas, homo perfectos et verus) and Gnosis appear as a pair of aeons, occupying a prominent place in the whole series.

In the Valentinian systems the pair of aeons, Anthropos and Ekklesia, occupy the third or fourth place within the Oydods, but incidentally we learn that with some representatives of this school the Anthropos took a still more prominent place (first or second; Hilgenfeld, Ketzergeschichte, p. 294 seq.).

Old women were employed as go-betweens, and the marriage ceremony was conducted by a priest who after moral exhortations united the young couple by tying their garments together in a knot, after which they walked seven times round the fire, casting incense into it; after the performance of the marriage ceremony, the pair entered together on a four days' fast and penance before the marriage was completed..

A pair of coiled nephridial tubes (n) formed of a file of perforated `' drain-pipe "cells, with ciliated tag-like" flame "cells (f), open into a contractile bladder (bl), FIG.

Very constantly a pair of simple sacklike glands open into the stomach, and probably represent the hepato-pancreatic glands of other Invertebrates.

They consist of a pair of tubules with an intracellular lumen running up the sides of the body, at times merely sinuous, at others considerably convoluted.

There may be one, a pair, or rarely more, the outer ones being more or less rudimentary.

Typically there are two pairs - a proximal, more or less approximated on the postero-dorsal surface, and a distal pair, more widely separate.

But the proximal pair are often fused into a single median antenna (supplied, however, by two nerves), and in one case at least the distal pair may be similarly fused.

Each pair has a single insertion on the inner wall - the one pair near the free extremity of the limb, the other near its attachment; the bands run up, one of each pair on each side, and run right round the body forming an incomplete muscular girdle, the ends approximating in the median line.

It presents a single pair of muscles attached along its inner wall which run up and form a muscular girdle round the body in its posterior third.

On either side is attached a dorsolateral and ventro-lateral appendage, each with a fan-like plumose termination consisting of compound hairs or setae, found elsewhere only among arthropods (q.v.); each of these is moved by muscles running upwards towards the neck and arising immediately under the trochal disk, the inferior ventro-lateral pair also presenting muscles which form a girdle in the hind region of the body.

Trochus a pair of ridges or horseshoe open in front.

However different in structure Trilobites may be, they all agree in possessing a head-shield usually semi-circular in shape, which results from the fusion of apparently five segments, and bears, except in some blind forms, a pair of large reniform compound eyes like those of the king-crab (Xiphosura).

This head-shield is succeeded by a varying number of free segments, each of which consists of a medium convex tergal piece and a pair of arched lateral plates, the pleura, of which there is one on each side.

A pair of the latter was articulated to the sides of a moderately wide dorsal plate on each segment of the body, and similar limbs were attached to the ventral surface of the head-shield behind the mouth.

As in all Arachnida there is only a single pair of appendages in front of the mouth, and these were onebranched, long and filiform and acted as antennae.

It must not indeed be assumed that those of the first pair were in all cases antenniform.

To this day there are numerous traces in popular belief, especially in Germany, of respect for the snake, which seems to be a survival of ancestor worship, such as still exists among the Zulus and other savage tribes; the "house-snake," as it is called, cares for the cows and the children, and its appearance is an omen of death, and the life of a pair of house-snakes is often held to be bound up with that of the master and mistress themselves.

Under a different aspect, the pair were regarded as the guardians of women in childbed and of new-born children.

On the other hand, resemblance to that genus is shown by the reduction of the upper incisors to a single pair.

In the European Miocene Listriodon, which also occurs in the Indian Tertiaries, the molars have a pair of transverse ridges, like those of the proboscidean Dinotherium; but the genus is believed to be related to the Oligocene Doliochoerus and Choerotherium, in which these teeth show a more normal type of structure.

The first pair of intersections may be either real or imaginary; we proceed to discuss the second pair.

The equation x 2 +y 2 =o denotes a pair of perpendicular imaginary lines; it follows, therefore, that circles always intersect in two imaginary points at infinity along these lines, and since the terms x 2 +y 2 occur in the equation of every circle, it is seen that all circles pass through two fixed points at infinity.

In the case of non-intersecting circles, it is seen that the minimum circles of the coaxal system are a pair of points I and I', where the orthogonal circle to the system intersects the line of centres; these points are named the " limiti,ng points."

The chief points in which they vary are - (1) in the structure of the ctenidia or branchial plates; (2) in the presence of one or of two chief muscles, the fibres of which run across the animal's body from one valve of the shell to the other (adductors); (3) in the greater or less elaboration of the posterior portion of the mantle-skirt so as to form a pair of tubes, by one of which water is introduced into the sub-pallial chamber, whilst by the other it is expelled; (4) in the perfect or deficient symmetry of the two valves of the shell and the connected soft parts, as compared with one another; (5) in the development of the foot as a disk-like crawling organ (Arca, Nucula, Pectunculus, Trigonia, Lepton, Galeomma), as a simple plough-like or tongueshaped organ (Unionidae, &c.), as a re-curved saltatory organ (Cardium, &c.), as a long burrowing cylinder (Solenidae, &c.), or its partial (Mytilacea) or even complete abortion (Ostraeacea).

A pair of renal tubes opening right and left, rather far forward on the sides of the body, are always present.

A pair of genital apertures, connected by genital ducts with the paired gonads, are found right and left near the nephridial pores, except in a few cases where the genital duct joins that of the renal organ (Spondylus).

It, as in other Mollusca, is not a blood-space but develops from the coelom, and it communicates with the exterior by the pair of renal tubes.

A pair of large glandular outgrowths, the so-called " liver " or great digestive gland, exists as in other Molluscs.

A pair of pedal otocysts, and a pair of osphradia at the base of the gills, appear to be always present.

In Pholas dactylus we find a pair of umbonal plates, a dors-umbonal plate and a dorsal plate.

Section across the axis of a ctenidium with a pair of plates - flattened and shortened filaments - attached.

The filaments take on a secondary grouping, the surface of the lamella being thrown into a series of halfcylindrical ridges, each consisting of ten or twenty filaments; a filament of much greater strength and thickness than the others may be placed between each pair of groups.

A pair of ducts (ai) lead from the first enlargement of the alimentary tract called stomach into a pair of large digestive glands, the socalled liver, the branches of which are closely packed in this region (af).

United with these ganglia on the outer sides are the osphradial ganglia, above which the epithelium is modified to form a pair of sense-organs, corresponding to the osphradia of other Molluscs.

Formerly the posterior pair of ganglia were identified as simply the osphradial ganglia, and the anterior pair as the cerebral, pleural and visceral ganglia united into a single pair.

There is, however, no evidence of the union of a visceral pair with the cerebro-pleural.

This deficiency is very usual in the class; at the same time, many Lamellibranchs have tentacles on the edge of the mantle supplied by a pair of large well-developed nerves, which are given off from the cerebro-pleural ganglion-pair, A, When free swimming, shows the two dentigerous valves widely open.

In them the foot has a flat ventral surface used for creeping, as in Gastropods, the byssus gland is but slightly developed, the pleural ganglia are distinct, there is a relic of the pharyngeal cavity, in some forms with a pair of glandular sacs, the gonads retain their primitive connexion with the renal cavities, and the otocysts are open.

The tenth abdominal segment carries a pair of jointed cerci which are often elongate, and the feelers are always long, while the jaws are usually feeble and membranous, though the typical parts of a mandibulate mouth are present - mandibles, maxillae with inner and outer lobes and palps, and second maxillae (labium) whose lacinae are not fused to form a ligula.

In the absence of cerci the Corrodentia are more specialized than the Isoptera and Plecoptera, but some of them show a more primitive character in the retention of vestigial maxillulae - the minute pair of jaws that are found behind the mandibles in the Aptera.

When wings are present the front pair are much larger than the hind pair, and the neuration is remarkable for the concresence of the median with the After Marlatt, Bull.

Its limbs, especially the hinder pair, are long; and the feet remarkable for the great development of the lateral pair of hoofs and for the freedom of motion The Musk-deer (Moschus moschiferus).

Bottlenoses feed on cuttle-fishes and squills, and are practically toothless; the only teeth which exist in the adult being a small pair at the front of the lower jaw, concealed beneath the gum during life.

These degrees were, when necessary, repeated along the stem by the employment of a pair of compasses till 80 degrees were marked off.

Both sexes carry lyrate horns; the shoulder-height of an adult male is about 30 in., and an average pair of horns measures 14 in.

Such organs are absent in Mollusca in the adult state, but a pair of nephridia usually occurs in the larva.

There is usually one pair of coelomic ducts leading from the pericardium to the exterior, and these are the excretory organs or kidneys, formerly known as the organs of Bojanus.

In the majority of Mollusca the gonads are provided with a pair of ducts of their own.

In animals which exhibit typical segmentation or metamerism, such as segmented worms (Chaetopoda), each segment or metamere possesses its own coelomic cavity, a pair of coelomic ducts, and a pair of nephridia.

The structure of the Mollusca in the greater number of cases agrees with the hypothesis that the primitive form was unsegmented, and therefore had but one pair of coelomic ducts and one pair of nephridia.

Among the Amphineura we find one pair of coelomic ducts in the Aplacophora, two pairs in the Chitons.

It is possible therefore to regard the latter condition as secondary, and to conclude that the separate genital ducts have been derived from the original single pair of coelomic ducts, as in Lamellibranchs.

Assuming that these ancestral forms resembled the existing Nautilus in their internal anatomy, they had two pairs of renal ducts and one pair of genital ducts, which would apparently indicate, not a single metamere or unsegmented body, but three metameres.

The Dibranchia, with only one pair of branchiae, one pair of renal organs, and one pair of genital ducts, are much more recent, not appearing till the end of the Secondary epoch, and therefore must be regarded as descended from the Tetrabranchia.

On the whole, then, the most probable conclusion is that the original ancestral form of the Mollusca was unsegmented, possessed one pair of true nephridia, and one pair of coelomic ducts whose function was to conduct the generative products to the exterior.

At the point of the collar whence the nerve-cords arise are the cerebral ganglia; from these one pair of connectives passes to a pair of pedal ganglia, and another pair of connectives to a pair of pleural ganglia.

The special sense-organs are a pair of eyes on the head, a pair of otocysts or statocysts, and a pair of osphradia which have already been mentioned.