History of the development of the human ovum, with a comparative view of the development of the ova of mammalia and birds / translated and abridged from the German of G. Valentin ... by Martin Barry.

  • Gabriel Valentin
Date:
[1834?]
Catalogue details

Licence: Public Domain Mark

Credit: History of the development of the human ovum, with a comparative view of the development of the ova of mammalia and birds / translated and abridged from the German of G. Valentin ... by Martin Barry. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    in the uterus. The albumen, which is not wanting in the Mam- malia, very probably originates during the passage through the tubes. The enormous swelling of the ova, in their passage through the Fallopian tubes, is in part favourable to this. But an indication of chalazEe might perhaps be found in the lateral elongations, discovered by Prevost and Dumas, in very delicate ova of the dog. In the same way it may be presumed, that the membrane of the shell, or the chorion, originates in the tubes, entirely as the shell-membrane of the bird is formed first in the isthmus. Von Baer, indeed, supposes that the outer membrane of the ovulum, contained in the Graafian vesicle, becomes the chorion. But, on the one hand, all analogy is opposed to this, since, besides that, in such case, as he also maintains, the yolk- bag must be formed first in the tubes ; on the other hand, it was not until after maceration that he himself distinctly perceived another, outer membrane,—an appearance which is always re- peated in the eggs of fowls which have not yet a shell-membrane. It would be interesting to determine, whether, for the secretion of these different structures, there occur also different confor- mations of the raucous membrane of the tubes. When now the ovulum has passed out of the Graafian vesicle, the inner stratum of the latter, according to Von Baer, and in part also, according to Regner de Graaf, becomes, by exuberant growth, the so-called corpus luteum. This begins to take place while the ovulum is still contained in the Graafian vesicle. As soon, however, as the ovulum has left the vesicle, the greater part of the latter is filled with a reddish, fleshy mass. In the centre alone, under the opening, there is found a cavity, either empty or filled with an albuminous mass, which cavity seems to be largest in man. It appears that the opening now, first of all, closes, whilst afterwards the cavity becomes smaller, until, at length, it entirely disappears. There are thus found in the ovary, yellow, reddish or bluish, bodies, of greater or less size, which are known under the name of corpora lutea. These corpora lutea, falsely so called, (for in different animals they have constantly different colours,) are universally and pro- perly regarded in the present day as the surest sign of a destroy- ed Graafian vesicle, and of an escaped ovulum, and, therefore, of impregnation having taken place. Although their form and ori- gin have been justly indicated by earlier observers, my own obser- vations on rabbits enable me to add yet many not unimportant particulars. The process here is the following. In consequence of conception, there arises a considerable congestion of blood to- wards the ovaries in general, and towards single Graafian ve- sicles in particular. The latter become pervaded with nets of fine blood-vessels, and increase in volume, though the larger ve- sicles alone seem to be comprehended in the process. With the commencement of this change, however, there appears, from the
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