ON THE DOMESTIC FOWL. 253 



In the case of the female chickens there was no substantial dif- 

 ference in the rate of growth in the three lots until after an age of 

 about 150 days was passed. During the next 25 days the controls 

 grew faster than the chicks from treated parents. At and after 200 

 days of age, however, the offspring of treated parents (one and 

 both) showed a higher mean body weight than the controls. We 

 have t-he following set of comparative mean body weights at 250 days 

 of age, obtained by interpolation on the curves. 



Comparative Mean Body Weights at 250 Days of Age. 



Absolute Weight. Relative Weight. 



Females ex untreated cj'c^ X untreated ?? i,g27.72 gm. 100 



Females ex treated J'c? X untreated $$ 2,020.38 gm. 105 



Females ex treated c?c? X treated ?$ 2,062.98 gm. 107 



At all ages in the case of the male chicks, and in all ages but two 

 (12.5 and 19.5 days) in the case of the female chicks, the mean body 

 weight of the offspring having both parents alcoholic was higher than 

 that of the offspring having one parent only, the father, alcoholic. 

 The differences are, for the most part, insignificant in comparison 

 with their probable errors, but the uniformity with which the " both 

 parents treated " curves maintain their superiority over the " father 

 only treated " curves is noteworthy, and significant. 



There are no distinctive differences in relative variability between 

 the three different lots of chicks. In general the relative variability 

 tends to diminish after an age of about 30 days is past. 



The evidence derived from a study of the growth of the chickens 

 in this experiment lends no support to the view that parental alcohol- 

 ism necessarily reduces the vitality of the offspring or induces degen- 

 eracy. On the contrary the data plainly indicate that the offspring 

 of alcoholized parents are in some degree superior in vigor and 

 vitality to those from untreated parents. 



8. Deformities in the F^ Progeny. — One of the most striking 

 features of Stockard's results on the alcoholization of guinea pigs 

 is that a considerable percentage of the progeny of treated parents 

 exhibit gross malformations of various organs, particularly the 

 eyes. In the present experiments with poultry, nothing of this sort 

 has made its appearance. The proportion of such abnormal chicks 



