"Ovum" Quotes from Famous Books
 ... features of interest, and cannot fail to retain its importance as an introduction to the study of embryology. The four principal phases in the development are: (1) Blastula, (2) Gastrula, (3) Flagellate Embryo, (4) Larva. The segmentation or cleavage of the ovum which follows upon fertilization terminates in the achievement of the blastula form, a minute sphere of cells surrounding a central cavity. Then follows the phenomenon of gastrulation, by which one-half of the blastula is invaginated into the other, so as to obliterate the segmentation cavity. The ...
— Project Gutenberg Encyclopedia
... the types of structure which are permanent in the lower forms of animal life. Thus, in the zoological chain, there are beings of all grades, from the most simple in structure to the most complex; and the most complex animal, in its development from the ovum or egg, passes through all these grades of structure, ending in that which is above all, and distinctively its own. 'Without going into tedious details, man presents, as regards the most important of his constituent structures, his nervous system, the successive characteristics of an avertebrated ...
— The Continental Monthly, Vol. 3, No. 1 January 1863 - Devoted To Literature And National Policy • Various
... many people there are, even in the middle class, who fail to recognise the fact that the egg (ovum) produces the caterpillar or "grub" (larva), which, after a due season of preparation, produces the chrysalis (pupa), which latter, lying quiescent for a variable period, either in the ground or in other situations favourable for its development, ...
— Practical Taxidermy • Montagu Browne
... forms—would, if it occurred, be merely an extreme case of variation in the Darwinian sense, greater in degree than, but perfectly similar in kind to, that which occurred when the well-known Ancon Ram was developed from an ordinary Ewe's ovum. Indeed we have always thought that Mr. Darwin has unnecessarily hampered himself by adhering so strictly to his favourite "Natura non facit saltum." We greatly suspect that she does make considerable jumps in the way of variation now and then, ...
— Darwiniana • Thomas Henry Huxley
... up therein a frame similar to the parents? In other words, what is there that presides over the preservation of the species, working out the miniature duplicate of the parents' configuration and character? It is the protoplasm, no doubt; and the female ovum contains protoplasm in abundance. But neither the physicist nor the chemist can detect any difference between the primordial germ, say of the fowl, and that of a female of the ...
— Five Years Of Theosophy • Various
... for the libido is always active even when it is directed to a passive aim. The second, the biological significance of masculine and feminine, is the one which permits the clearest determination. Masculine and feminine are here characterized by the presence of semen or ovum and through the functions emanating from them. The activity and its secondary manifestations, like stronger developed muscles, aggression, a greater intensity of libido, are as a rule soldered to the ...
— Three Contributions to the Theory of Sex • Sigmund Freud
... better provided with muscles and fins than the tiny little fry which come out of the eggs of the improvident species. For example, the cod-fish lays nine million odd eggs; but anybody who has ever eaten fried cod's-roe must needs have noticed that each individual ovum was so very small as to be almost indistinguishable to the naked eye. Thousands of these infinitesimal specks are devoured before they hatch out by predaceous fish; thousands more of the young fry are swallowed alive ...
— Science in Arcady • Grant Allen
... to come in heat at the usual times, shows little disposition to take the bull, and fails to conceive when served. Her trouble is the same in kind, namely, fatty degeneration of the ovaries and of their excretory ducts (Fallopian tubes), which prevents the formation or maturation of the ovum or, when it has formed, hinders its passage into the womb. Another common defect in such old, fat cows is a rigid closure of the mouth of the womb, which prevents conception, even if the ovum ...
— Special Report on Diseases of Cattle • U.S. Department of Agriculture
... them often, and was at much pains with them: He prevailed so far with Gordon, that he desired to be relaxed from the sentence of excommunication which he was under; and accordingly Mr. Blair did the same: The other two, who were bishops sons, died impenitent.—Mali corvi malum ovum. ...
— Biographia Scoticana (Scots Worthies) • John Howie
... the very start of his life—that is, at the moment when the ovum and spermatozoon which are to produce him have united—numerous well-defined tendencies to future behavior. Between the situations which he will meet and the responses which he will make to them, pre-formed ...
— Introduction to the Science of Sociology • Robert E. Park
... traits are congenital, but acquired. Native traits date back to the original constitution of the child, which was fully determined at the time when his individual life began, nine months before birth. The "fertilized ovum", formed by the combination of two cells, one from each of the parents, though microscopic in size and a simple sphere in shape, somehow contains the determiners for all the native or inherited traits of the ...
— Psychology - A Study Of Mental Life • Robert S. Woodworth
... Journal of the Anthropological Institute, Vol. V., p. 329, Jan., 1876), and I find a remarkable anticipation of Weismann's theories which I think should be noticed in a preface to the translation of his book.[17] He argues that it is the undeveloped germs or gemmules of the fertilised ovum that form the sexual elements of the offspring, and thus heredity and atavism are explained. He also argues that, as a corollary, "acquired modifications are barely if at all inherited in the correct sense of the word." He shows the ...
— Alfred Russel Wallace: Letters and Reminiscences Vol 2 (of 2) • James Marchant |
