CHAPTER VIII. 



THE MANNEK IN WHICH A CONNECTION IS ESTAB- 

 LISHED BETWEEN THE FOETUS AND UTEKUS. 



Implantation of the Ovum. — The blastodermic vesicle is 

 represented in Fig. 69. In its course down the Fallopian tube 

 the somatopleure, which forms its outer wall, becomes differen- 

 tiated into four areas, shown diagram matically in Fig. 74, by a 



embryo body sta ik 



Fig. 74. — Showing what becomes of the Somatopleure of the Blastodermic Vesicle. 



species of folding, already described and shown in transverse section 

 in Fig. 72 and in longitudinal section in Fig. 75. The embryo 

 becomes enclosed in a double capsule of somatopleure — the outer 

 the prechorion and the inner the amnion. But, as is shown in 

 Fig. 75, the amnion in man is peculiar in that it forms practically 

 no tail fold; the head fold grows backwards like a hood until it 

 comes in contact with the caudal pole of the embryo. When 



