352 



HUMAN UTERUS AND FCETAL APPENDAGES. 



that the coelom is entirely obliterated, that the yolk-stalk has usually been com- 

 pletely resorbed, and that only traces of the allantois can be seen, Y . The blood- 

 vessels have grown; there are two arteries, A, A' , and a single vein, V . Around 



p-iG. 211. — Cross-section of a Human Umbilical 



Cord at Term* 

 A, A' , Umbilical arteries much contracted. V, Um- 

 bilical vein. F, Remnant of allantois. X^^diams. 



TTIES 



Fig. 212. — Section of the Allantois from a 



Human Umbilical Cord of Three Months. 



ent. Allantoic entoderm, mes. Mesoderm. X 340 



dianis. 





i 









AH 





Fig. 213. — Connective Tissue from the Umbilical Cord of a Human Embryo of 21 mm. Stained 



WITH Alum Cochineal and Eosin. X 54° diams. 



n. Nucleus. /, Protoplasmic network. 



