J. W. H. Harrison 



45 



in size over their untreated relatives is just what Pearl noted in his 

 fowls. 



In all cases the copulations proved successful, and an abundance of 

 fertile eggs was laid. As a matter of fact every egg in the cages changed 

 colour and thereby displayed its fertility. The exact total of those 

 deposited in the cages by fertilised females, and in chip boxes by virgin 

 females, is supplied with other essential facts in Table III. 



Average number of ova per female 



130-5 



124-3 



Again as tested by the average number of ova per female, the un- 

 treated individuals were distinctly inferior to those which had undergone 

 treatment with alcoholic fumes. Nor did the matter rest there ; although 

 every egg was fertile not every one hatched, and there were marked 

 differences in the number of zygotes which perished in the shell, the 

 mortality rate being obviously less when a treated imago figured as a 

 parent. As with other statistical data, this is best set out in tabular 

 form so that the precise values may be comprehended at a glance. 



Pairing 



Control ^ ^ X Control $ $ 

 Control (J ,^ X Alcoholised $ $ 

 Alcoholised (J <? x Control $ $ 



Although the ova from the controls were laid in the four days 

 following June I6th, those from the mating of an alcoholised male and 

 a control female in the four days after June 19th, and those from the 

 reciprocal cross after June 21st, the ova hatched in the reverse order ; 

 those from the last-named pairing emerging on July 1st, 2nd, and 3rd, 

 those from the second lot on July 2nd, 3rd, and 4th, and those from the 

 untreated controls spreading themselves out over the period between 

 July 8th and July 14th, both days being included. Here we first see 

 indicated that acceleration in development manifested by the offspring 

 of treated parents at every stage. 



