J. W. H. Harrison 47 



three ( = 46 °/^). This result is the more significant when one recollects 

 that all three lots were descended from the same great-grandparents 

 and grandparents and had thus been twice inbred — a fact explaining 

 the low vitality of the controls which the administration of alcohol to 

 the parents had apparently surmounted in the case of the others. 



Nor was the superiority where the parentage included an alcoholised 

 individual confined solely to the low death rate; it was exhibited in the 

 general rapidity of feeding up and growth as can readily be gleaned 

 from the facts and data given. Even more remarkable was the fact that, 

 despite the greater rate of growth, the members of the same two broods 

 attained a much greater size in both sexes. To enable this to be 

 grasped with facility use is once more made of a table. Profiting from 

 my experience gained with their parents, when cripples were not avail- 

 able for measurement, in compiling Table VI, instead of taking the 

 imaginal wing expanse I extracted the pupae from their cocoons, weighed 

 them and utilised the pupal weights which appear, classified according 

 to brood and sex, below. 



TABLE VI. 



Males Females 



Number of Average Number of Average 



Brood Individuals Weight Weight Individuals VV^eight Weight 



^^ConS$i'^ "" 1 ^^ 3-79 grms -165 grm 27 5-25 grms -194 grm 



AkohSdt? } ^« 2-55 grms -142 grm 23 407 gm.s -177 grm 



Control? V } 12 1-44 grms -12 grm 15 202 grms -135 grm 



The insects began to come out on August 24th when a male pro- 

 ceeding from the pairings in which the alcoholised male took part 

 appeared. Others followed by degrees until August 27th when four 

 males and one female had been bred. On that date two females repre- 

 senting the reverse cross joined company. The first control, a male, 

 only emerged on September 1st when the other two batches were nearly 

 all out : in fact, two-thirds of the treated male x untreated female lot 

 and one-half of the other were already on the setting boards. Never- 

 theless, within the ensuing seven days, every insect had been reared 

 save for one control which had died in the cocoon as an unchanged 

 larva. 



Just as one might anticipate from their greater pupal weight, the 

 imagines from the alcoholised series were much the larger insects in both 

 sexes. In addition to this, they displayed their robustness in a very 



