40 Effects of Alcohol on Selenia bilunaria 



critical period of gainetogenesis, from the earliest spermatogonial or 

 oogonial division. to the development of the perfect spermatozoon or 

 ovum, results more important still might be obtainable. For such an 

 experiment a lepidopterous insect,particularly a double brooded Geometer, 

 was eminently suitable, and to carry it out a stock of the bivoltine race 

 of Selenia bilunaria was secured. 



Immediately after I had made these arrangements. Pearl's papers, in 

 which he gives complete details as to his experiments on the adminis- 

 tration of methyl and ethyl alcohols and ether to poultry, came to hand. 

 So different were the results described there from those of Stockard, 

 and so apparently contradictory to them were they, that it almost seemed 

 impossible for one to harmonise them in the slightest. Stockard found 

 that his second generation guinea-pigs were so affected that the various 

 litters included a heavy proportion of more or less malformed weaklings : 

 and this very nearly represents the state of affairs in similar experi- 

 ments, conducted with lead salts on the same animals, by Cole, Bach- 

 huber, Weller and others. Pearl, on the contrary, found that the 

 progeny of alcoholised fowls was measurably superior in several important 

 respects to the offspring of untreated individuals. Almost in complete 

 agreement with Pearl's work were the indications of Nice's white mice, 

 and of Elderton and Pearson's studies on the influence of parental 

 alcoholism in human beings. The scope of my projected experiments 

 was greatly enlarged by the possibility that they would throw some 

 light on the seeming discrepancy between the conclusions to be drawn 

 from the various sets of work enumerated. Furthermore, as a group of 

 animals far removed from the Mammalia or Aves was involved, the value 

 of the work was greatly enhanced, whether its indications went to 

 corroborate or to contradict any or all of the data just mentioned. 



The questions then I set out to answer were 



(1) Can I by the continued administration of ethyl alcohol so affect 

 the germ cells of Selenia bilunaria as to repeat the conditions of Morgan's 

 Drosophila cultures where hereditable variations appeared in very un- 

 usual numbers ? 



(2) Failing this, are the progeny of parents submitted to the action 

 of the deleterious agent significantly affected by it ? 



(3) If not, do the actual phenomena encountered approximate to 

 those observed in the case of Pearl's fowls and of Cole's white mice ? 



(4) And generally, what effects, somatically or otherwise, has the 

 agent used on the treated individuals or their offspring ? 



