PARENTAL ALCOHOLISM AND THE PROGENY 247 



would form zygotes under normal circumstances are definitely 

 put out of commission by the treatment. While such inactiva- 

 tion of germ cells is undoubtedly the primary factor in reducing 

 the fertility, the other two factors also play some part. 



All the evidence at hand from observations on the behavior 

 of these birds indicates that factor (c), preferential mating in 

 favor of untreated females, is second in importance to (b) in 

 reducing the percentage of fertility of the eggs of treated females. 

 Observations of the males in the breeding pens indicate that the 

 alcoholized females are not sought by the males with either the 

 eagerness or the frequency that the untreated females are. Just 

 what is the basis of this preference does not yet appear. Factor 

 (a) probably plays a minor part in the diminished fertility of 

 the eggs of the treated females. 



4. Comparing the different males- it appears that, taking the 

 data from all matings both with treated and untreated females, 

 the ether cf gave the highest fertility (69.9 per cent fertile), the 

 ethyl d^ the next highest (63.3 per cent fertile), and the methyl 

 cf considerably lower (37.6 per cent fertile). All of these figures 

 are lower than the mean of the random sample of 22 normal 

 matings of untreated males with untreated B. P. R. females 

 recorded in table 2. Those matings gave 76.8 per cent fertile 

 eggs. There appears to be no doubt that the process of zygote 

 formation (fertilization) in these treated matings was signifi- 

 cantly impaired by the treatment in every case. This impair- 

 ment was most serious in matings of the methyl cT. His best 

 mating (2125) gave a percentage of fertihty, 76.3 per cent slightly 

 lower than the average for a random sample of matings of un- 

 treated matings in the same season. All cross-bred matings of 

 untreated males and females in 1915 gave 536 eggs infertile out 

 of 2628 set, or 79.6 per cent fertile. The methyl cf 's percentage 

 is significantly below this. 



5. The percentage of fertile eggs hatched is higher for the 

 matings of treated males, whether mated with treated or un- 

 treated females, than for the random sample of normal matings 

 in which both parents are untreated. It is also higher in these 

 treated matings than in all cross-bred matings in 1915, which 



