MODIFICATION OF THE GERM-CELLS IN MAMMALS 207 



The third and fourth columns contain similar records from the 

 matings of the fifteen normal females with normal males and 

 with alcoholic males. The twenty-six normal matings gave only 

 one failure, while the twenty-three matings with alcoholic males 

 failed to give results in five cases, or in 21.73 per cent of the trials. 

 The alcoholic males always give a high percentage of mating 

 failures even with normal females and, as this case shows, with 

 females giving only a low per cent of failure by normal males. 



The normal matings produced fifty-nine young, fifty-one of 

 which survived while only eight, or 13.55 per cent, died within 

 three months. This is an unusually low mortality record and 

 proves the ability of these females to produce strong viable young. 

 None of the offspring from the normal matings were defective. 



The same females produced by alcoholic males fifty young, 

 only thirty of which lived to maturity. Therefore, 40 per 

 cent of them were non- viable, which is three times more than was 

 the case with offspring from these females by normal fathers. 

 Ten per cent of the fifty offspring were defective. The contrast 

 between the two groups of results from the same females is so 

 great that the possibility of the difference being due to the 

 smallness of the numbers involved would seem to be completely 

 eliminated. The records in the entire table are perfectly con- 

 sistent and very clear cut. 



It would seem only proper to interpret such results, along 

 with the mass of evidence in the foregoing pages, as showing that 

 alcoholic guinea-pigs, whether directly treated or descended 

 from treated individuals, have had their ability to produce 

 strong, viable offspring definitely and decidedly lowered. And 

 it may be added in this connection that evidence from purely 

 male treated lines as well as that given by later generations from 

 the female treated and mixed lines, points directly to the fact 

 that the germ cells have been affected. The effects of this 

 modification are transmitted through several generations, only 

 to be lessened by the elimination through death and sterility of 

 the weakest individuals from the mating records and the con- 

 stant introduction of more and more normal germ plasm into the 

 Une by matings with the normal stock. 



