PARENTAL ALCOHOLISM AND THE PROGENY 269 



3. The mean hatching weights of the females are in all three 

 series shghtly greater than those of the males. The differences, 

 however, are entirely insignificant in comparison with their 

 probable errors. 



Tm'ning to the consideration of relative variability in hatch- 

 ing weight, as measured by the coefficient of variation, it appears 

 that the males are more variable than the females in all three 

 series. The differences, however, are not very large in propor- 

 tion to their probable errors, and can be regarded only as some- 

 what doubtfully significant. 



There appears to be no evidence that the relative variabihty 

 in respect of hatching weight has been in any way affected by 

 the alcohol treatment. 



VIII. GROWTH OF THE Fi PROGENY 



Growth, as measured by increase in body weight, is univer- 

 sally recognized by physiologists and by practical animal hus- 

 bandmen as one of the most valuable indices of innate consti- 

 tutional 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 frequency distributions giving the raw data on the growth 

 of the animals in these experiments are exhibited as Appendix 

 Tables I to XV inclusive. The constants deduced from these 

 distributions are given in tables 11, 12, and 13. Regarding the 

 collection of the growth data it may be said that weighings were 

 made at regular intervals according to a fixed schedule. For 

 purposes of analysis weighings for ages differing by but few days 

 were grouped, and regarded as concentrated at the central age 

 of the group. This amounts essentially to a first smooth of the 

 material. It is not our intention in the present paper to enter 

 upon any discussion of general problems of growth. It is desired 

 here merely to make a comparison between the offspring of 

 alcoholized and those of non-alcoholized parents. 



It will be noted by comparison of tables 11 to 13 that the 

 centered ages for which mean body weights are given are ir 



