THE PHYSIOLOGY OF REPRODUCTION 



Beneath the epithelioid layer in both areas the cells are drawn out 

 and pseudo-fibrous. The conditions for nutrition resemble those in 

 the very early human ovum, the trophoblast lying against a non- 

 vascular detritus-zone. But in the bat there is strong evidence of 

 phagocytosis. The epiblastic protoplasm, where it is in contact with 





VdaU 



FIG. 146. The placenta of the bat. (From Nolf's "Etude des modifications de 

 la ruuqueuse uterine pendant la gestation chez le murin," Arch, de JJiol., 

 vol. xiv., 1896.) 



m., Muscularis ; a., unaltered mucosa ; C.ep., epithelial layer ; gl., glands ; 



O.pp., paraplacental layer with blood-spaces (b) ; Art., artery running 



, towards trophoblast ; !>., vein ; TV., trophoblast with lacunae ; Vil. all., 

 allantoic villi. 



dead tissue, is " crammed with irregular granules, some fatty and 

 others coloured brown with safranin " (Xolf). The mouths of the 

 glands opening at the non-embryonic pole are filled with debris, and 

 their epithelium is degenerated and desquamated. As previously 

 mentioned, no gland-ducts are present in the conche paraplacentaire. 

 The blind ends of the glands are, however, distended with secretion, 

 and their epithelium is normal. 



Next a change occurs such as Hubrecht described in the hedgehog 

 (see p. 478). The endothelium of some of the vessels in the para- 



