THE DETERMINATION OF SEX. 



35 



some breeders of stock and birds, but is denied by other practical 

 authorities, and directly contradicted by the recent statistics of Stieda, 

 from Alsace-Lorraine, and of Berner, from Scandinavia. 



Summary 



of Statistics bearing on Relative Number of Males and Females. 



Observer. 



No. of 

 Births. 



Locality. 



Father 



older. 

 Proportion 

 of Males to 

 100 Females. 



Father of 

 equal age. 

 Proportion 

 of Males to 

 100 Females. 



Father 



younger. 



Proportion 



of Males to 



roo Females. 



Average 

 Propor- 

 tion of 



Males to 

 100 



Females. 



Remarks. 



Hofacker 



1,996 



Tubingen 



117.8 



92.0 



90-6 



107.5 





Sadler 



2,068 



England 



121. 4 



94.8 



86.5 



114.7 



-• 



Gohlert 



4,584 





108. 



93-3 



82.6 



105.3 





Legoyt 



52,311 



Paris 



104.49 



102.14 



97-5 



102.97 



•• 



Boulenger 



6,006 



Calais 



109.98 



107.92 



101.63 



107.9 





Nolrot 



4,000 



Dijon 



99-7 





116.0 



103.5 





Breslau 



8,084 



Zurich 



103.9 



103. 1 



117. 6 



186.6 





Stieda 



100,590 



Alsace- 

 Lorraine 



105.03 



•• 



108.39 



106.27 



Contradictory. 



Berner 



267,946 



Sweden 



104.61 



106.23 



107.45 



106.0 



Contradictorj' 

 (see text). 



The above table (in its upper part taken mainly from Hensen, after 

 (Esterlen) shows vividly how^ much the results of Stieda and Berner 

 conflict with the law of Hofacker and Sadler. In regard to Berner's 

 statistics, it ought to be further noted that the figures quoted refer to cases 

 where the father or mother is only from i to 10 years the older. If the 

 father be more than ten years older, the male majority is 103.54 ; if the 

 mother be more than ten years older, the proportion is 104.10 again, 

 against Hofacker's and Sadler's conclusion. Compared with the above 

 human statistics, Schlechter's results in regard to horses also militate 

 against the alleged law. 



In regard to plants, various naturalists have drawn attention to the 

 influence of age upon sex. The following observations are quoted by 



