BIOLOGY OF EGGS AND IMPLANTATION 



Fig. 14.3. Drawings of graphic reconstructions of a 16- and 32-somite human embryo. A. 

 The bhick dots within the circle represent the location of the germ cells in the yolk sac and 

 ventral wall of the hind-gut in the 16-somite embryo. B. Position of indi\-idual germ cells 

 (black dots) in the 32-somite embryo. Larger dots indicate an endodermal position. Few 

 germ cells remain in the ventral mesenchyme. (After E. Witschi, Contr. Embryol., Carnegie 

 Inst. Wasliington, 32, 67-80, 1948.) 



