Page:Proceedings of the Royal Society of London Vol 60.djvu/50

42 the segm enting germ inal area, by the parablast of mesoblastic ova.

I was under the impression when these observations were made, th at fat had never been found, in this form, in the placenta before. I find that I am to some extent anticipated by a paper in the ‘Archiv fur Gynaekologie,’ February, 1896. One of the authors (Aschoff) wished to examine a m alignant uterine growth, which he believed to be of the nature of Reci Before doing so, he examined several specimens of young hum an ova, in order, as he says, to learn something of the structure of growing chorionic villi. Some of the specimens he hardened in Flemming’s solution, and in all of these he found fat in th e plasmodial layer of the villi. Aschoff’s description of the fat deposit agrees very closely with that already given of my own specimen. “ An den Flemmingschen P raparaten ist das Syncytium dadurch ausgezeicbnet, dass es in seiner Randzone eine dichte A nhaufung feinster Fetttropfchen tragt. Dieselbe sind bald sehr fein, bald grobkornig, aber in den betreffenden A bschnitten des Syncytiums stets von gleicher Grosse .................Die Fetttropfchen iiberall sich finden, wo Chorionepithelzellen, in directesten Stoff wechselaustausch m it den Intervillosenraum entreten” (p. 531).

Aschoff scarcely appreciates the physiological importance of the observation, but there can be no doubt that his observations and my own are mutually confirmatory.

Through the kind hospitality of Professor de Lacaze-Duthiers, I was able to spend the spring and sum m er of last year at the marine laboratories of Banyuls-sur-M er and Roscoff, where I was chiefly engaged in studying the embryology of the Ascons. In Banyuls I obtained the larvae of Leucosolenia, H. sp., in June, and of L. reticulum, O.S. sp., in July. In Roscoff I found the larvae of L. variabilis, H. sp., all through August and the early p art of September,