Diagram /. 



Pang^enesis. 



(b^)(©c) 



Stage 2. 



mm 



Stage I? 



Stage I. 

 Diagram ///. 



Devolopment of 

 Identical Twins. 



Stage 5. 



stage 4. 



Stage 3. 



Stage I. 

 Diagram //. 



Continuity of 

 Germ-Plasm. 



Jo J ace p. 120 



