156 



ROSCOE E. HYDE 



in the germ plasm we should expect it to reappear only sUghtly 

 intensified in this case among the grandchildren, A study of the 

 528 pairs tested in the F2 generation verifies the expectation. 

 This case shows that sterility as it reappears among the grand- 

 children bears a more or less definite relation to the degree to 

 which it was put into the cross. The behavior of the sterility of 

 the truncates at this time is significant for their earlier history 

 shows that half the pairs were sterile. As stated, it was at first 

 my opinion that sterility was inherent in the strain, and that it 

 bore a causal relation to low productivity. But the above 

 results seem to show that sterility and low production of fertile 

 brothers and sisters are two entirely different things. Such a 



TABLE 16 b ^ 

 Woods Hole cf X truncate 9 ; reciprocal 16 a 



