446 



THE PHYSIOLOGY OF REPRODUCTION 



of glandular detritus and tlie compact layer, which in turn form a 

 symplasma and undergo ahsorption. Thus the fcetal structures reach 

 the spongy layer, in which the glandular cvls-dc-mc have expanded 

 to form large cavities sepai-ated by partitions, the niesenteriform 



tr^^^^'^S^^'f^^^^^^:^ 



Fig, 124. — The angioplasmode of the dog at the thirtieth day of pregnanc-\-. 

 (From Duval's " Le Placenta des Carnassiers," Juyrn. <Ir C Anat H dp la 

 Phys., 1893.) 



ms, Mesoblast ; tr, trophoblast ; ae, ectodermic arcades ; d, layei- of 

 glandular detiitu.s. 



lamelLv. Gradually the roof of this layer is alsn al)sorlied by the 

 trophoblast, and the ectodermal arcades at the tijjs of the villi gain 

 a permanent attachment to tlie niesenteriform lamelLr. At the same 

 time, by the further branching and penetration of the frotal meso- 

 derm in the angwplasmodc, the tissue is l^roken up into a series of 

 labyrinthine lamellae, which consist of a network of maternal vessels 

 clothed on each side by syncytial trophoblast. The meshes of the 



