384 
GENETICS: A. PEARL 
counted as but one single character. Finally with respect to two char- 
acter groups there is no difference between the alcohoHsts and the non- 
alcoholists. 
We may evaluate our results in general terms as follows: 
1. There is no evidence that specific germinal changes have been 
induced by the alcohoHc treatment, at least in those germ cells which 
produced zygotes. 
2. There is no evidence that the germ cells which produced zygotes 
have in any respect been injured or deleteriously affected. 
3. The results with poultry are in apparent contradiction to the results 
of Stockard and others with mammals. This contradiction is, however, 
probably only apparent and not real, paradoxical as such a statement 
may appear. 
4. The results with poultry are in a number of important respects 
in essentially complete agreement with those of Elderton and Pearson^ 
on parental alcohoUsm in man, and of Nice'* in mice. 
The interpretation of these results which seems to account best for 
all the facts is that the apparent discrepancy between avian and mamma- 
lian results is fundamentally due to a difference in degree of resistance 
of the germ cells to alcohol. Given the existence of variation in the 
vigor or resisting power of germ cells, which is certainly a fact, we have 
the necessary basis for the action of a selective agent. The hypothesis 
which we wish to suggest is that alcohol acts as such a selective agent 
upon the germ cells of alcoholized animals, ehminating the weak and 
permitting the survival of the vigorous and highly resistant. 
Detailed evidence in support of this hypothesis is presented in the 
complete paper. The experiments are being continued. 
^ Some account of this work has already appeared. Cf. Pearl, R., On the effect of 
continued administration of certain poisons to the domestic fowl, with special reference to 
the progeny, Froc. Amer. Phil Soc, 55, 243-258 (1916). 
2 Cf. for summary and bibliography of earher papers Stockard, C. R., and Papanicolaou, 
G., A further analysis of the hereditary transmission of degeneracy and deformities by 
the descendants of alcoholized mammals, Amer. Nat., 50, 65-88, 144-177 (1916). 
' Elderton, E. M. and Pearson, K., A first study of the influence of parental alcoholism 
on the physique and ability of the offspring, Eugenics Lab. Mem., 10, 1-46 (1910). 
(Second edition.) 
* Nice, L. B., Comparative studies on the effects of alcohol, nicotine, tobacco smoke, and 
caffeine on white mice. I. Effects on reproduction and growth, /. Exper. ZooL, 13, 133- 
153 (1912). 
