252 PEARL— EFFECT OF CERTAIN POISONS 



fluence on this character it has been so shght as not to be statistically 

 discernible in samples of the size here dealt with. 



6. Hatching Weight of F^ Progeny. — In the present series of 

 experiments there is no significant difference in mean hatching weight 

 between the offspring of treated males and the offspring of normal 

 untreated control males when both are mated to normal untreated 

 females. The slight differences which do appear are of the same 

 order of magnitude as their probable errors. 



Both the male and the female offspring of matings in which 

 both parents were treated have a larger mean hatching weight 

 (i. e., are heavier when hatched) than the offspring of either com- 

 pletely normal control matings, or of matings in which the father 

 only is treated. The differences here are relatively large and are 

 statistically significant in comparison with their probable errors. 



7. Grozvth of the F-^ Progeny. — Growth, as measured by increase 

 in body weight, is universally recognized by physiologists and by 

 practical animal husbandmen as one of the most valuable indices of 

 innate constitutional vigor and vitality which it is possible to obtain. 

 On this account it was thought to be of first-class importance to 

 study the growth of the offspring from alcoholized as compared with 

 untreated parents. 



The offspring of alcoholized parents, whatever the nature of the 

 mating, showed a higher mean adult body weight than oft'spring of 

 untreated parents of the same breeds mated in the same way. This 

 is true of both sexes. 



In the case of the male chickens there was no substantial differ- 

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

 about 100 days was passed. From that point on the male offspring 

 of treated (j^J* X untreated and treated 5? grew at a more rapid rate 

 than the controls. The differences in mean body weight for a given 

 age became increasingly large as the age advanced. At 200 days 

 of age we have by interpolation on the curves the following set 

 of comparative mean body weights. 



Comparative Mean Body Weights at 200 Days of Age. 



Absolute Weight. Relative Weight. 



Males ex untreated Jc^ X untreated $? 2,392.32 gm. 100 



Males c.r treated c?c? X untreated $$ 2,668.97 gm. 112 



Males f'.r treated c^c^ X treated $? 2,815.25 gm. 118 



