FCETAL NUTRITION: THE PLACENTA 



459 



is in contact with maternal l)loo(l or decidaa. It increases fioni the 

 twelfth to the sixteenth day, then it decreases, and a week later 

 disappears altogether. In the maternal placenta fat first appears 

 in the decidual cells which are nearest the troplioUast. They show 



nsvvuv^'""^ 



-r^ 



rf. 



^ in 



# ^^ i^ 



-9 



.a 



. ''' \ # 



.i^i^ '•-^''■[ 



Fig. 130. — Iron granules in the jjhicenta of the rabliit at the eighteenth day 

 of pregnancy. (Chipnian.) 



f(, Iron granules in mesoblast ; li, iron granules in multinucleate decidual 

 cells ; f/, iron granules in ectodermal tubules. 



no sign of tlegeneratiim at this time, and they probahly .scarte the 

 fat globules. After increasing fur a few days, it diminishes with 

 the atrophy of the decidual cells, and finally appears as fatty debris. 

 Fat is also present in the proliferating endothelium, and later in the 

 fibrin lamina- of the uterine sinuses. 



In the new-l:iorn fietus the main store of fat is contained in the 

 subcutaneous tissue. It is remarkable that it does not appear in 



