264 



RAYMOND PEARL 



TABLE 7 



Showing the sex ratio in matings of treated black Hamburg 6 6 ^4. . loith untreated 



B. P. R. d'd' 



B. with treated B. P. R. 9 9 



^ These probable errors are calculated by the usual formula for the probable 

 error of a percentage: 0.6744898 . 



VE-LS., where p denotes the percentage of 

 N 



which the probable error is desired, q 

 observations on which p is based. 



100 — p, and A'" = the total number of 



Evidently these figures give no ground for asserting that the 

 relative proportions of the sexes produced are significantly differ- 

 ent in the alcoholic and normal control series. If the treat- 

 ment has had an influence on this character it has been so slight 

 as not to be statistically discernible in samples of the size here 

 dealt with. 



