PARENTAL ALCOHOLISM AND THE PROGENY 249 



Summarizing the general features of the above results regard- 

 ing production of offspring by alcoholized parents it may be 

 said that the average fertility of eggs (i.e., proportion of zygotes 

 formed) is diminished and the average hatching power of the 

 fertila eggs is increased after alcoholization of the parents. The 

 reduction in average fertility of the eggs is due primarily to the 

 effect on the germ cells, and in some part to the fact that alco- 

 holized females are not as attractive to the males as untreated, 

 and hence are discriminated against in the matings, and further- 

 more probably in some part to the fact that the oviduct of the 

 treated female does not furnish so favorable an environment for 

 sperm as the oviduct of untreated females. The net result is 

 that alcoholized parents produce on the average fewer offspring 

 per mating unit than do normal, untreated parents under con- 

 ditions otherwise similar. 



In all these results on the production of offspring there is no 

 definite evidence that any deleterious blastophthoric effect has 

 been produced by the poisoning upon the germ cells which pro- 

 duce zygotes. On the contrary what we do have is clear evidence 

 that the treatment acts as a selective agent on the germ cells, 

 entirely eliminating from zygote formation the weaker and less 

 vigorous. The gametes which survive this selective process and 

 take part in zygote formation are the most vigorous and resistant 

 part of the germ cell population. Their superiority is clearly 

 demonstrated in the significantly higher per cent of fertile eggs 

 hatched when both parents are treated. This means that the 

 embryos formed by these germ cells are superior in vigor and 

 vitality to embryos formed by an unselected sample of germ 

 cells as in normal reproduction. As we proceed we shall see 

 that this initial superiority is maintained throughout the life 

 history of the offspring of treated parents. The quantitative 

 analysis of the different factors concerned in the reproductive 

 process, which has been presented in this section, taking into ac- 

 count the correlations, constitutes convincing evidence that the 

 poisons used act as selective agents on the germ cell population. 



