FCETAL MEMBRANES OF CHIROMYS MADAGASCARIENSIS. 1151 



lumina as small homogeneous spherules and as a deeply staining 

 coagulum. Where the glands are enlarged and not actively 

 secreting, the lining cells are cubical. In Lepilemur the glands 

 are very similar to those of Chiromys, but we have observed dis- 

 tinct evidence of branching. Jenkinson (16) states that they 

 " open at the base of depressions " ; we find that in this species 

 the localised areas on which the glands open may or may not be 

 depressed, and that they are characterised by the mnrked 

 thickening and folding of the uterine epithelium. These areas 

 are situated opposite specially thickened patches of the chorionic 

 trophoblast, to which we shall later make reference. In Nycti- 

 cebtts the glands are larger than in Chiromys, but are otherwise 

 similar. Hubrecht (8) states that they open on the bottoms of 

 the crypts in which the villi are situated. In Galago they open, 

 according to Strahl (14), partl}^ on depressed bare areas in 

 relation \i ith chorionic vesicles, partly (in the main horn) inde- 

 pendently (p. 193). Strahl is of opinion that inGalago extravasated 

 blood in the mucosa is taken up by the uterine gland cells, and 

 is utilised for the nutrition of the foetus. In none of the material 

 Ave have examined (Chiromys, Lejnlemur, jVycticebus) have we 

 seen any trace of extravasated blood in the corium of the 

 mucosa, though the later is richly supplied with vessels. 



FtETAL Membranes. 

 1 . A llanto-cho7'ion. 



The allanto-chorion, or chorion as we may term it for brevity 

 (PI. I. fig. 1), forms an exact cast of the interior of the uterus, 

 extending from the apex of one horn to the apex of the other, 

 filling the entire corpus uteri and prolonged (in specimen A) by 

 a blunt conical process into the cervix as far as the os externum. 

 Its surface is covered almost all over by characteristic villous 

 outgrowths in the form of more or less broad swollen pleats 

 marked superficially by delicate sinuous convolutions, presenting 

 an appearance as nearly as possible similar to the figure given 

 by Strahl (15, pi. 36. figs. 4 & 5) of the chorion of a 30-mm. 

 foetus of Propithecus. The surface of the folds thus appears to be 

 less elaborated tha,n in the Lemurs described by Turner (5, 

 p. 575 &r, 7, p. 279) or in the later stages of Propithecus 

 (Strahl, 16, p. 273). The primary pleats are set for the most 

 part transversely to the length of the chorionic sac, becoming 

 more regularly disposed in each horn in parallel circular wreath- 

 like bands. 



In specimen B (Pis. III., lY. figs. 4, 5, & 7-10), the laminar 

 arrangement is in parts masked to some extent by the depth of the 

 secondary foldings which break up the primary pleats and produce 

 a more lobulated surface than in the specimen A (PI. lY. fig. 9). 

 This lobulation must not be confused with the appearance pre- 

 sented by tlie characteristic polygonal villi of the genus JVycticebits 



