r 



LIFE-HISTORY OF ROTIFER 245 



appearance, nervous reactions, and ability to reproduce" (p. 120). 

 When the progeny of alcohohzed animals, themselves not sub- 

 jected to the treatment, were mated the data were such that "it 

 may be concluded that animals as far as three generations re- 

 moved from the direct alcohol treatment are still differentiated 

 from the control iii regard to the weight of the litters in which 

 they are born, the tendency of the matings to result in failure 

 . . . ." (p. 164). In general, then, the alcoholization of guinea- 

 pigs produces some change in the germ cells which is still evident 

 in the third generation of non-treated progeny, even when normal 

 germplasm is thrown into the hereditary stream at each mating. 



In the domestic fowl, Pearl ('17 a, b, c,) has used the same 

 general method of treatment, in this case treating the birds for 

 only one hour per day. In appearance ''the treated animals 

 themselves are not conspicuously worse or better than their 

 untreated control sisters and brothers" (p. 185). The capacity 

 to reproduce was not influenced since "neither the total amount 

 nor the distribution of egg production were significantly different 

 in the treated birds from what they were in the controls" (p. 186). 

 But ''the proportion of fertile eggs .... was materially reduced 

 in the matings in which one or both individuals had been treated" 

 (p. 294). At the close of the account of the experiment the 

 conclusion was reached that ''There is no evidence from these 

 experiments that the treatment of individual fowls with ethyl 

 alcohol had any deleterious effect upon those germ cells which 

 form zygotes. The treatment rendered many germ cells in- 

 capable of forming zygotes at all, but those which did form 

 zygotes had plainly not been injured in any way" (p. 295). 



Thus among the higher organisms the evidence points in 

 opposite directions, that secured from mammals indicating the 

 persistence of the influence of the environmental agent as far 

 as the third generation of the untreated progeny, that secured 

 from birds not indicating that there is a change produced in the 

 germ cells by the subjection to alcohol. Among the lower 

 organisms Whitney ('12) has studied the effect of alcohol on the 

 rotifer Hydatina senta. He reared the organisms in culture 

 fluid plus I, I, and 1 per cent ethyl alcohol for twenty-eight 



