HUMAN EMBRYO IN THE SIXTH STAGE. 



139 



FIG. 84. HUMAN OVUM, SAID TO BE FROM FIFTEEN TO EIGHTEEN t>AYS OLD. (Compare footnote, page 138.) 

 The chorion has been opened and spread out to show the embryo and its adnexa. Al, Body-stalk containing the 

 allantoic diverticulum. Am, Amnion surrounding the embryo. Vi, Yolk-sac. (Ajter Caste.) 



