Its tendency to undergo cyclical changes.
They live for some time in water or mud, occasionally entering the bodies of water snails, but undergo no change until they reach the lung of a frog, when the cycle begins anew.
Such a colony may undergo two principal modifications.
(5) The victim might be naturally sacred or might have to undergo sanctification.
If the observer takes up a suitable position near water, his coat is often seen to be covered with the cast sub-imaginal skins of these insects, which had chosen him as a convenient object upon which to undergo their final change.
In an age when, with the evolution of the feudal organization cf society, even everyday costume was becoming a uniform, symbolizing in material and colour the exact status of the wearer, it was natural that in the parallel organization of the Church the official vestments should undergo a similar process of differentiation and definition.
The Territorial Army and its reserve (members of which undergo two short periods of training) are, however, allocated to local service.
If educated at home, the child (after two years of the compulsory period has expired) must undergo a yearly examination, and if it is unsatisfactory the parents will be compelled to send him to a public or private school.
The eggs of the female give rise to embryos within the body of the mother; her other organs undergo a retrogressive change and serve as food for the young, until the body-wall only of the mother remains as a brown capsule.
The last part of the peninsula to undergo the Gallicizing influence was the papal dominion.
As regards growth after hatching, all beetles undergo a "complete" metamorphosis, the wing-rudiments developing beneath the cuticle throughout the larval stages, and a resting pupal stage intervening between the last larval instal1 and the imago.
But many of the simpler P Y ler P forms of life may undergo desiccation to such an extent as to arrest their vital manifestations and convert them into the semblance of not-living matter, and yet remain potentially alive.
Fleas are oviparous, and undergo a very complete metamorphosis.
The Nematoda which are parasitic during their whole life may similarly be divided into two classes - those which undergo their development in a single host, and those which undergo their development in the bodies of two distinct hosts.
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.
As they pass into this position they undergo a longitudinal splitting by which the chromatin in each chromosome becomes divided into equal halves.
Those germs which do not ripen during the season undergo a process of resorption, and in the winter the whole ovary dwindles to often a diminutive size.
Earlier still the sun must have reached to where Neptune now revolves on the confines of our system, but the mass of the sun could not undergo an expansion so prodigious without being made vastly more rarefied than at present, and hence we are led by this mode of reasoning to the conception of the primaeval nebula from which our system has originated.
The white blood-cells, or leucocytes, undergo other changes.
As in other cases where animal colonies are formed by organic union of separate individuals, there is ever a tendency for the polyp-colony as a whole to act as a single individual, and for the members to become subordinated to the needs of the colony and to undergo specialization for particular functions, with the result that they simulate organs and their individuality becomes masked to a greater or less degree.
The growth of an organic being is simply a process of enlargement, as a particle of dry gelatine may be swelled up by the intussusception of water; its death is a shrinkage, such as the swelled jelly might undergo on desiccation.
They are due to hypertrophy of young tissues, which may undergo profound alterations subsequently, and occur on all parts of the plants.
They are more easily seen, when the nucleus is about to undergo mitosis, at the ends of the spindle, where they form the centres towards which the radiating fibres in.
There is also an unmistakable development in the laws; and the priestly legislation, though ahead of both Ezekiel and Deuteronomy, not to mention still earlier usage, not only continues to undergo continual internal modification, but finds a further distinct development, in the way of definition and interpretation, outside the Old Testament - in the Talmud.
Any change which a substance may chance to undergo was simply due to the discarding or taking up of some proportion of the primary " elements " or qualities: of these coverings " water," " air," " earth " and " fire " were regarded as clinging most tenaciously to the essence, while " cold," " heat," " moistness " and " dryness " were more easily cast aside or assumed.
Compounds containing an oxy in addition to an aldehydic or ketonic group) undergo both condensation and oxidation when treated with phenylhydrazine, forming compounds known as osozones; these are of great importance in characterizing the sugars (q.v.).
The addition of a little of the acid to glue renders it more tenacious; skins to be used for making leather do not undergo decomposition if steeped in a dilute solution; butter containing a small quantity of it may be kept sweet for months even in the hottest weather.
For 0=2, (a l a i +v 2 a 2) w; either v l or cr 2 will vanish if a1a2=A2=o; but every term, in the development, is of the form (222...)Ar and therefore vanishes; so that none are left to undergo reduction.
[[[Stress And Magnetization]] magnetized under very heavy loads, the wire was indeed found to undergo slight contraction.
If now a gradually increasing magnetizing force is applied, the needles at first undergo a stable deflection, giving to the group a small resultant moment which increases uniformly with the force; and if the current is interrupted while the force is still weak, the needles merely return to their initial positions.
If the aperture and wave-length increase in the same proportion, the size and shape of the diffraction pattern undergo no change.
At Waterloo he was wounded in the right arm and had to undergo amputation, but he quickly learned to write with his left hand, and on the conclusion of the war resumed his duties as secretary to the embassy at Paris.
Should there be much loss of tissue of an organ, the cells of the remaining part will enlarge and undergo an active proliferation (hyperplasia) so that it may be made up to the original amount.
From whatever cause the tissues become disorganized and undergo fatty degeneration, the fatty acids may become liberated and combine with the alkalies to form potash and soda soaps.
In 1872, Hoppe-Seyler (1825-1895) gave a new beginning to our knowledge of the chemistry of secretion and of excretion; and later students have increased the range of physiological and pathological chemistry by investigations not only into the several stages of albuminoid material and the transitions which all foodstuffs undergo in digestion, but even into the structure of protoplasm itself.
In South Australia boys had to undergo three stages of initiation in a place which women were forbidden to approach.
If a system be removed from all communication with anything outside of itself, the whole amount of energy possessed by it will remain constant, but will of its own accord tend to undergo such transformations as will diminish its availability.
Although several species belonging to the second class occasionally enter the bodies of water snails and other animals before reaching their definitive host, they undergo no alteration of form in this intermediate host; the case is different, however, in Filaria medinensis and other forms, in which a free larval is followed by a parasitic existence in two distinct hosts, all the changes being accompanied by a metamorphosis.
Thus the gonads are covered over by at least four layers of epithelium, and since these are unnecessary, presenting merely obstacles to the dehiscence of the gonads, they gradually undergo reduction.
Those who were unwilling to accept evolution, without better grounds than such as are offered by Lamarck, and who therefore preferred to suspend their judgment on the question, found in the principle of selective breeding, pursued in all its applications with marvellous knowledge and skill by Darwin, a valid explanation of the occurrence of varieties and races; and they saw clearly that, if the explanation would apply to species, it would not only solve the problem of their evolution, but that it would account for the facts of teleology, as well as for those of morphology; and for the persistence of some forms of life unchanged through long epochs of time, while others undergo comparatively rapid metamorphosis.
Most remarkable is the presence of a number of beetles along the seashore between tide-marks, where, sheltered in some secure nook, they undergo immersion twice daily, and have their active life confined to the few hours of the low ebb.
This cavity contains an irregular mass of whitish tissue, the fat-body, consisting of fat-cells which undergo degradation and become more or less filled with urates.
The pits leading from these lengthen into tubes, and undergo repeated branching as development proceeds.
There are likewise maps on smaller scales, which undergo frequent revision.
Most of the polynitro compounds are not volatile, but undergo deco Imposition on heating.
The alkaline carbonates undergo only a very slight decomposition, even at a very bright red heat.
It is certain, however, that no such classification can be considered final at present, but must undergo continual revision in the future.
The result of this treatment is that the comparatively heavy oils undergo dissociation, as shown by the experiments of Thorpe and Young, into specifically lighter hydrocarbons of lower boiling points, and the yield of kerosene from ordinary crude petroleum may thus be greatly increased.
Numerous varieties of soaps are made; the purposes to which they are applied are varied; the materials employed embrace a considerable range of oils, fats and other bodies; and the processes adopted undergo many modifications.