> 75- Section through human chorion, amnion, embryonic disk, and yolk sac. Peters. 



Compare with Fig. 74. 



Yolk sac 



Amnion 



Neural groove "^EE 



Chorion 



FIG. 76. Dorsal view of human embryo, two millimeters in length, with yolk sac. 



von Spee, Kollmann. 

 The amnion is opened dorsally. 



