44 



Effects of Alcohol on Selenia bilunaria 



involved, has, in all probability, no definite import, although it is con- 

 ceivable that the exaggeration of the disparity in the case of the treated 

 lot points to some superior resistive powers on the part of the female 

 zygotes to the effects of alcohol vapour. 



Emergence commenced with the appearance of a control male on 

 June 15th, to be followed at intervals by others until every single pupa 

 had yielded its imago. The other group* began to put in an appearance 

 on June 18th, but of the ten pupae only seven, two males and five 

 females, emerged. The remainder died shortly after pupation whilst the 

 alcoholisation was yet being continued. 



Thirty per cent, therefore died as pupae. Of those emerging two, 

 one of each sex, were cripples. The male was a large strong insect and 

 owed its crippling to accidental injury ; the female, on the other hand, 

 was a weakling and did not succeed in disentangling itself from the 

 pupal integument. Had it not been freed artificially it would, un- 

 doubtedly, have perished within the pupal envelope. 



As the imagines came out they were caged up in three separate 

 muslin cages, the controls being paired inter se, and reciprocal pairings 

 being made between them and opposite sexes of the "alcoholists." 

 Owing to the fact that I never had a treated male and female out 

 together, the fourth possible pairing, that between a male and a female 

 treated example, proved unobtainable. When all of the insects had 

 died, they were removed from the pairing cases and carefully measured 

 with results seen in the appended table. It is perfectly evident that, in 



both sexes, the insects which have been placed under the action of ethyl 

 alcohol fumes during their growth and development periods are dis- 

 tinctly larger in size. In spite of the low numbers concerned, I feel 

 certain that this is no chance effect, more especially when this superiority 



