364 



ROSCOE R. HYDE 



47-8 



4'} I 



41 1 



4l.S> 



ffif.6 



(,4-^ 



Diagram C Showing the effect on fertility of crossing the extracted truncates 

 B (F2 truncates descended from the truncate cf) with the high-producing grand- 

 parental stock. 



Diagram D Showing the effect on fertility of crossing the extracted truncates 

 A (F2 truncates descended from the truncate 9 ) with the high-producing grand- 

 parental stock. 



Diagram E Showing the effects on fertility of crossing the extracted truncates A 

 (F2 truncates descended from the truncate 9 ) with the extracted truncates B (Ft 

 truncates descended from truncate c?). 



behavior of the fertiUty of the extracted truncates toward the 

 Woods Hole stock is practically the same whether the truncate 

 flies descended from the truncate grandmother or truncate grand- 

 father. 



It is to be emphasized that the fertility of the truncates has been 

 practically doubled (as determined by testing brother and sister) 

 as a result of crossing out and extracting ; and yet a marked degree 

 of incompatibility exists between the gametes of the extracted 

 truncates. For example, diagram C shows that the extracted 

 male B produced 85.1 good sperm and the extracted female B 

 produced 81.7 good eggs and yet the fertility as shown by testing 



