246 



UROGENITAL SYSTEM 



first composed of a layer of trophectoderm (of Langhans) with the outlines of its 

 cuboidal cells sharply defined (Fig. 241 A). This layer forms and is covered by 

 a syncytium, the trophoderm. In the later months of pregnancy as the villi 



Fig. 239. — Section through a normal placenta of seven months in situ (Minot): Am, amnion; CAo, 

 chorion; Vi, root of villus; vi, sections of small villi ramifying in the intervillous blood spaces; D, deep 

 spongy layer showing remnants of large flattened glands; Ve, uterine vessel opening into intervillous 

 spaces; Mc, muscular wall of uterus. 



