Observations on the development of Anableps Gronovii (Cuv. and Val.) : read Sept. 20, 1854 / by Jeffries Wyman.

  • Wyman, Jeffries, 1814-1874.
Date:
[1857]
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the development of Anableps Gronovii (Cuv. and Val.) : read Sept. 20, 1854 / by Jeffries Wyman. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    6/14
    it, to be visible. Externally, the sac is covered with what appear to be parallel projecting lines, extending from the sides of the abdomen to its most prominent part (Figs. 6 & 8.) These Valenciennes describes as vascular striae, (stries vasculiformes.*) Such was not the nature of these markings in the specimens which I examined; but, when placed under the microscope, were found to form a peculiar structure, which possibly may have some connection with the process of nutrition in their peculiar method of gestation. The sac itself seemed nearly homogeneous in structure, but the striae are made up of spherical, or in some cases, pyri- form or cylindrical, papillas or villi, (Fig. 8,) projecting from the surface, and arranged so nearly together in a linear series as to give the appearance of a continuous band. In regard to the minute structure of these papillae, as far as it could be deter- mined from an alcoholic specimen, they consist externally of an exceedingly thin membrane, inclosing a vast number of minute granules; no vessels were seen in connection with them nor in the membrane to which they were attached. There was no appearance of any communication between the cavity of the papilla and that of the membrane to which it was attached. Within the latter, but more nearly in contact with the intestines, there was a second more delicate membrane, which seemed to be a continuation of the parietal peritoneum. No traces of the yelk were found in connection with the intestines. III. The third specimen is much longer and measures ten inches in length ; the ovary had been ruptured, so that some of the foetuses had escaped into the cavity of the abdomen, but the whole number of young taken from the parent was much greater than in the preceding case, namely, eighteen ; one of these was projecting from the genital opening. They generally resembled the preceding except in size, though the eyes had become more prominent (Fig. 6,) and the iris now * Op. cit. ex fol. de planche, 539.