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.

  • Valentin, G. (Gabriel), 1810-1883.
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.

    10/40 (page 6)
    tion of the disk, then admits with some decision of being recog- nized, when the germinal vesicle is certainly to be perceived. The foregoing contains, perhaps, the most important part of the history of the ovum of the bird, so long as it is found in the ovary, from the first moment of its origin until the time when it leaves the ovarial stratum, and the vascular lamella, contain- ed within the latter, to pass into the oviduct. We thought it required, first, to give this sketch in order to be able to under- stand, and justly to estimate, the phenomena occurring in the Qvary of the Mammalia and of Man. The former, the ovary, consists, namely, of the peritoneal covering, of a more or less fibrous couch, (stroma of Baer,) and of blood-vessels. In this substance there lie inclosed a greater or less number of spherical or spheroidal vesicles, the size of which is quite different in dif- ferent animals, as well as in individual parts of the same ovary. Although this structure of the ovary was known before the time of Regner de Graaf, the latter has the merit of having with evidence, pointed out, that after every impregnation these vesi- cles, in number corresponding with that of the future embryos, burst, discharge their content, and are then changed into a fleshy, yellow, or reddish mass. Hence these structures were called vesiculos Graa/iancB) or more correctly, since de Graaf himself, in many places, used the expression. Jvlliculi Graafiani. The analogy with the ovary of birds was in this manner, to a cer- tain extent, established ; for it was pointed out that in Mamma- lia, that organ which, sometimes after the older authors, was called testes muliebres, sometimes after Steno, ovaria, discharg- ed after impregnation, a certain number of ovula into the tubes like the ovary of birds. In the next place, it was to be main- tained that the Graafian vesicles themselves were these ovula, as also in the ovary of birds, the yolk acquired very considera- ble volume before it passed into the oviduct. But Regner de Graaf himself had found, by a series of experiments on the first effects of impregnation in rabbits, that the ovula, in the earliest days after conception, so long as they were contained in the tubes, or in the horns of the uterus, were much smaller than the Graafian vesicles, especially as the latter, immediately after a fruitful connection, increased considerably in volume. He had therefore arrived immediately at the negative result, that the vesicles of the ovary themselves could not be the ovula passing over into the uterus. On the contrary, they burst at their point of greatest size, discharged their content, hence contained in the first place a cavity in their centre, and were gradually changed, as this cavity became filled up, into the corpora lutea. The next question then was, whether thefolliculi contained in them- selves the far smaller ovula, or only discharged a fluid, which