183 



This author has made (46) a similar statement for the placenta 

 of the Ferret. 



Lüsebrink has come to the same conclusions. He says that it 

 is possible to 'gut verfolgen' the epitheliutn over the villi; but 

 in his Fig. 2 it is not very easy to see this, and in his Fig. 3, 

 although the deep end of the ectodermal villus is certainly covered by 

 a distinct layer of cells it is not possible to tracé this layer into 

 the cells, marked Ep, at the surface, which lie immediately under- 

 neath the 'chorionic ectoderm'. 



In Fleischmann's first paper a figure is given of the disappe- 

 arance of the uterine epithelium in the Fox; in the same paper 

 he states that he was unable to rnake this out in the Cat. In a 

 second paper, however, he states that the epithelium of the surface 

 does disappear in this animal also, and that the syncytium of the 

 placenta is formed from the degenerated epithelium of the glands. 

 In a third paper he has made a formal retractation, and admits, 

 with Strahl and Lüsebrink, the persistence of the epithelium. It 

 is curious, however that his figure (PI. XIII. Fig. 2) directly 

 contradicts the final statement of his views. 



Marchand (27) derives the syncytium from glandular epithelium. 

 Heinricius (15, 16) agrees with Du val with respect to the disap- 

 pearance of the uterine epithelium in both the Dog and Cat ; he 

 differs from him, however, in deriving the syncytium from the 

 subepithelial connective tissue. This syncytium in later stages is 

 largely degenerate. 



Lastly, Strahl (47) quotes Bonnet as saying (in a paper which 

 I have unfortimately not been able to see) that a temporary plas- 

 modial layer is formed from the trophoblast, while the uterine 

 epithelium remains intact. 



It is evident that in the early stages of the placentation of 

 the Carnivora we are confronted by processes the correct inter- 

 pretation of which is attended with more than ordinary difificulty. 



In many of the mammals which we have previously considered 

 the glands are pushed away from the region of the future placenta 

 by a proliferation of connective-tissue. Here however, the placental 



