Alternation Sentence Examples
Hence the alternation is of the type termed metagenesis.
The battle represents the eternal conflict between light and darkness, the alternation of day and night.
But rhyme was not attempted, and the syllabic metre of Japan was preserved, the alternation of 5 and 7 being, however, dispensed with.
Certainly, over this period, the incumbents included graduates of both universities, apparently in strict alternation.
The alternation of singers also predominates in these genres.Advertisement
The cycle of development taken by the Malacocotylea has been generally regarded as an alternation of one or more asexual generations with a sexual one.
The Ascomycetes, at least the Carpoascomycetes, exhibit a well-marked alternation of sexual and asexual generations.
Upon the evidence it would seem therefore that so far as Nemalion is concerned an alternation occurs comparable with that existing in the lower Bryophyta where the sporophyte is relatively small, being attached to and to some extent parasitic upon the gametophyte.
It is probable, therefore, that we have here a sharp alternation of generations, both generations being, however, precisely similar to the eye up to point of reproduction.
A cold north-west wind, with frosty nights and sunny days in alternation, tends to incite the flow, which is more abundant during the day than the night.Advertisement
They typically present two structural forms, the non-sexual hydroid and the sexual medusoid; in such a case there is an alternation of generations (metagenesis), the hydroid giving rise to the medusoid by a sexual gemmation, the medusoid bearing sexual cells which develop into a hydroid.
The complicated alternation of generations seen in such a form as Aurelia does not occur in the more primitive genera.
Parthenogenesis is prevalent in the Branchiopoda and Ostracoda, often in more or less definite seasonal alternation with sexual reproduction.
Each group is made up of an alternation of soft marls or clays and hard limestones or sandstones.
In the Abietineae the phloem consists of parenchyma and sieve-tubes only, but in most other forms tangential rows of fibres occur in regular alternation with the parenchyma and sieve-tubes.Advertisement
Turning to fossil Asteroidea, we find the earlier ophiurids scarcely distinguishable from the asterids, while in the alternation of the ambulacrals, which undoubtedly correspond to the flooring-plates of Edrioaster, both groups approach the Pelmatozoan type.
The first volume published of his posthumous works was the exquisite and splendid Thedtre en liberte, a sequence if not a symphony of seven poems in dramatic form, tragic or comic or fanciful eclogues, incomparable with the work of any other man but the author of The Tempest and The Winter's Tale in combination and alternation of gayer and of graver harmonies.
Neither the doctrine of Hobbes, that deliberation is a mere alternation of competing desires, voluntary action immediately following the " last appetite," nor the hardly less decided Determinism of Locke, who held that the will is always moved by the greatest present uneasiness, appeared to either author to require any reconciliation with the belief in human responsibility.
The structure is in all respects that typical of roots, as shown by the centripetal primary wood, and the alternation of xylem and phloem groups observable in exceptionally favourable young specimens.
Those of us who have always made the standard vowel alternation will have no such trouble.Advertisement
It has an alternation of generation reproductive style, with the gametophyte being the dominant generation.
Do woodlice show alternation in their natural habitat or is it an artifact of this apparatus?
They exhibit alternation of generations; the dominant phase (the kelp plant) is the sporophyte.
It was also found that rapid alternation between 0% and 100% opacity was an extremely successful aid to spotting differences between witnesses.
Thus we see in history a regular alternation of ebb and flow in the tide of human progress.Advertisement
However, smaller slacks nearer the sea may in any case be part of a cyclic alternation of building and erosion phases.
There is no clear pattern for this constant alternation between using his own hand and someone else's.
Thus in Cunina octonaria, the ovum develops into an actinula which buds daughteractinulae; all of them, both parent and offspring, develop into medusae, so that there is no alternation of generations, but only larval multiplication.
Fortunately, however, the Gregorian canto fermo associated with it is of exceptional beauty and symmetry; and the great 16th century masters either, like Palestrina, left it to be sung as plain-chant, or obviated all occasion for dramatic expression by setting it in versicles (like their settings of the Magnificat and other canticles) for two groups of voices alternatively, or for the choir in alternation with the plain chant of the priests.
It is commonly assumed that the Trachylinae are forms which have lost the alternation of generations possessed by them ancestrally, through secondary simplification of the life-cycle.
The polyp of the Leptolinae has reached the limit of its individual development and is incapable of becoming itself a medusa, but only produces medusa-buds; hence a true alternation of generations is produced.
In Gonionemus the actinula becomes fixed and polyp-like, and reproduces by budding, so that here also an alternation of generations may occur.
It will be seen elsewhere, however, that whatever view may be held as to the origin of metagenesis in Hydromedusae, in the case of Scyphomedusae (q.v.) no other view is possible than that the alternation of generations is the direct result of larval proliferation.
Both sexual and asexual reproduction occur, but there is usually no definite succession of the two modes, marking that alternation of sexual generation (gametophyte) and asexual generation (sporophyte) which characterizes the higher groups.
The Archegoniatae are characterized by a well-marked alternation of gametophyte and sporophyte generations; the former bears the sexual organs which are of characteristic structure and known as antheridia (male) and archegonia (female) respectively; the fertilized egg-cell on germination gives rise to the spore-bearing generation, and the spores on germination give rise directly or indirectly to a second gametophyte.
In accordance with the prevalent antithetic view of the alternation of generations in these plants (see PLANTS, REPRODUCTION or), the forms distinguished as sporophyte and gametophyte are not homogenetic; consequently their leaves are not homologous, but are only functionally similar (homoplastic; see infra).
In the first place, the normal life-cycle of plants and animals exhibits what is known as alternation of generations, so that any individual in the chain may resemble its grand-parent.
The conditions favourable to the production of coal seem therefore to have been-forest growth in swampy ground about the mouths of rivers, and rapid oscillation of level, the coal produced during subsidence being covered up by the sediment brought down by the river forming beds of sand or clay, which, on re-elevation, formed the soil for fresh growths, the alternation being occasionally broken by the deposit of purely marine beds.
It succumbed to the ceaseless alternation of tolerance and persecution which characterized the Arab rule in Egypt, and the mass of the Coptic people became unfaithful to the Church.
It is proved that the specific instances on which Barrande's generalizations were founded were due to his misinterpretation of the overturned and faulted strata, but his conception of the simultaneous existence of two faunas, one of more ancient and one of more modern type, and of their alternation in a given area, was based on sound philosophical principles and has been confirmed by more recent work.
She there wrote her Appel a l'impartiale posterite, those memoirs which display a strange alternation between self-laudation and patriotism, between the trivial and the sublime.
The Trachylinae, on the other hand, are above all oceanic forms, and have no polyp-stage, and hence there is typically no alternation in their life-cycle.
In Cunina parasitica, however, the ovum develops into an actinula, which buds actinulae as before, but only the daughter-actinulae develop into medusae, while the original, parent-actinula dies off; here, therefore, larval budding has led to a true alternation of generations.
In such cases the original parent-actinula does not itself become a medusa, but remains arrested in development and ultimately dies off, so that a true alternation of generations is brought about.
There is often a marked alternation in the production of vegetative and flowering shoots respectively; and, sometimes, from various circumstances, the flowering shoots are not produced for several years in succession.
In the paraschists, though fossils are exceedingly rare, sedimentary structures such as bedding and the alternation of laminae of fine and coarse deposit may frequently be preserved.
The oldest strata, consisting of gypsiferous marls, are referred to the Muschelkalk and show an alternation of lagoon with marine conditions.
Some authors looking upon these as parthenogenetic ova regard the developmental cycle as one composed of an alternation of parthenogenetic and of sexual generations.
Maxwell had himself, at an early stage of his theory, tested the absorbing power of gold-leaf for light, and found that the effective conductivity for luminous vibrations must be very much greater than its steady ohmic value; it is, in fact, there a case of incipient conductivity, which is continually being undone on account of the rapid alternation of force before it is fully established.
The middle ages were far more disastrous for the Monophysites than for the Nestorians; in their case there was no alternation of rise and decline, and we have only a long period of gradual exhaustion to chronicle.
The views of Adler as to the alternation of generations of numerous gall-flies have been fully confirmed, it having been ascertained by direct observation that the galls and the insects produced from them in one generation are entirely different from the next generation; and it has also been rendered certain that frequently one of the alternate generations is parthenogenetic, no males being produced.
In the first place, we find in this group two distinct types of person or individual, the polyp and the medusa (qq.v.), each capable of a wide range of variations; and when both polyp and medusa occur in the life-cycle of the same species, as is frequently the case, the result is an alternation of generations of a type peculiarly characteristic of the class.
The life of the parasites while in the insect is characterized by an alternation of active periods, during which multiplication goes on, with resting-periods, when the Trypanosomes become attached to the epithelial cells of the host.
The indifferent parasites exhibit an alternation of resting, attached phases with active periods, during which they multiply actively and become very abundant in the insect.
Again, in Kentucky and Tennessee, there is a double alternation of sandstone and limestone in the plateau-making strata; and as the skyline of the plateau bevels across these formations, there are west-facing escarpments, made ragged by mature dissection, as one passes from the topographically strong sandstone to the topographically weak limestone.
Of all the periods marked out by the motions of the celestial bodies, the most conspicuous, and the most intimately connected with the affairs of mankind, are the solar day, which is distinguished by the diurnal revolution of the earth and the alternation of light and darkness, and the solar year, which completes the circle of the seasons.
There is no satisfactory explanation of this break in the regular alternation of successive whorls; the outer whorl' of stamens arises in course of development before the inner, so that there is no question of subsequent displacement.
Some manufacturers devote themselves exclusively to the home trade, and some exclusively to foreign trade, but there is a large class with what may be called a margin of alternation, which serves to redress the balance as business in one or other of the sections is good or bad.
His minority, 1272-1277, was an alternation of palace revolutions and civil wars, in the course of which his brave Kumanian mother Elizabeth barely contrived to keep the upper hand.
Life-history in some cases very complex and with well-marked sexual process and alternation of generations, in others much reduced; basidium (promycelium) derived usually from a thick-walled spore (teleutospore).
Life-history always very simple, no wellmarked alternation of generations; basidium borne directly on the mycelium.
There is thus in all the Basidiales an alternation of generations, obscured, however, by the apogamous transition from the gametophyte to sporophyte.
The following table is an adaptation of a scheme devised by Klebs, and indicates the inter-relationships of the marked alternation of generations which of genera- b' dominates the life-history of the higher plants.
Altogether it is difficult on morphological grounds to resist the conclusion that Florideae present the same fundamental phenomenon of alternation of generations as prevails in the higher plants.
And since this rule has been found to hold good for all the archegoniate series and also for the flowering plants where, however, the gametophyte generation has become so extremely reduced as to be only with difficulty discerned, it is natural that when alternation of generation is stated to occur in any group of Thallophyta it should be required that the cytological evidence should support the view.
The west coast, with its alternation of sea and promontory, of rugged mountains and fertile valleys, its bright and varied scenery, and its fine climate, is almost a part of Europe.
Corresponding with each pair of myotomes, and subject to the same alternation, two pairs of spinal nerves arise from the neurochord, namely, a right and left pair of compact dorsal sensory roots without ganglionic enlargement, and a right and left pair of ventral motor roots composed of loose fibres issuing separately from the neurochord and passing directly to their termination on the muscle-plates of the myotomes.
How many times the alternation of sex may take place in a season is not known.
The development from the egg may be direct, or may take place with an alternation of generations (metagenesis), in which a non-sexual individual, the so-called scyphistoma or scyphopolyp, produces by budding the sexual medusae.
The complete life-history, with its regular alternation of gametophyte and sporophyte, is now known in all except a few rare genera of recent Pteridophyta, and will be described in connexion with the several groups.
For a discussion of this view, which regards the alternation of generations in Pteridophytes as antithetic and the two generations as not homologous with one another, reference may be made to the works of Celakovsky and Bower.
A number of facts regarding the Algae, and also those relating to such deviations from the normal life cycle as apogamy or apospory, may be regarded as lending support to this view, which, in contrast to the theory of antithetic alternation, has been called that of homologous alternation.
The life-cycle of the Leptolinae consists of an alternation of generations in which non-sexual individuals, polyps, produce by budding sexual individuals, medusae, which give rise by the sexual process to the non-sexual polyps again, so completing the cycle.