196 CHARLES R. STOCKARD AND GEORGE N. PAPANICOLAOU 



such a fertilization are inferior and more apt to die during early 

 developmental stages, and thus a greater number of male em- 

 bryos would survive and be born. 



When the alcoholic mother or early female treated lines were 

 mated with untreated normal males, the sons were inferior to the 

 daughters. Here again, taking into consideration the two 

 structurally different classes of spermatozoa, the normal males 

 paired with alcoholic females contribute a smaller amount of 

 normal chromatin to the complex producing male offspring than 

 to that giving rise to the female offspring. The records of the 

 males are hence inferior to those of the females. And in the 

 present connection such males might be expected to suffer a 

 higher early prenatal mortality and so give rise to the very low 

 sex-ratios shown by the columns from 'only mother alcoholic' 

 and 'only female ancestors treated.' 



Such reasoning from the present data is admitted to be highly 

 speculative; nevertheless, if the morphological differences which 

 have been found to exist between the two classes of spermatozoa 

 in a number of animal species have any significance, they must 

 sooner or later be recognized as the underlying cause of such 

 results as table 6 shows for sex-ratios in alcoholized guinea-pigs. 



These ideas also account for the fact that the sex-ratios of 

 the normal animals is out of accord with the ratios of all the 

 treated groups on the basis of the average litter size. This dis- 

 cord was recognized as a possible objection to the purely dif- 

 ferential sex mortality explanation previously discussed. In the 

 present connection we may take the following position. 



The normal group has been subjected to no injurious action 

 which has tended to modify the expression of the sex-ratio, 

 while in the alcoholized groups there is evidence of a deviation 

 from the normal, in one direction or the other, depending upon 

 the combination concerned. And this deviation is imagined 

 to be due to a lower fertilizing ability on the part of certain 

 spermatozoa. 



There is another question to be considered in connection with 

 the differences in response on the part of the two classes of sper- 

 matozoa; that is, the possibility of certain eggs being more sub- 



