STATISTICAL STUDIES ON THE VARIATION 

 OF STAGBEETLES. 



BY 

 Tetslo Inukai. 



Zoological Jiutitiitioit, Imperial University, Saffcro. 



(With 8 figures and 4 tables) 



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Ouetelet (1871) was the first who worked out the variabilit)' of human 

 bodies by the statistical method, and established his law which later enabled 

 Galton and others to recognize the coincidence of the variation cur\-e with 

 the binomial cur\e. Actual investigations, so far completed, support the law 

 by which the general phases of variation in the organic world are explained. 



In the }ear of 1894 Boteson worked on the variation of the stagbeetle 

 (Xylotmpes gidcon} and, later on that of the earwig {Forficula auiicidaria) 

 and detected the dimorphic curve of frequency of variates. He was followed 

 by a series of investigators on this question including de Vries (1895) on 

 Chrysanthemum, \\'eldon (1895) on crabfish, Heincke (1897) on herring, Jen- 

 nings (191 1 ) on Paramaecium, Goldschmidt (1897) on moth and so forth. 



As is well known, Bateson distinguishes" 'high' and 'low' individuals, ap- 

 plying the terms respectively to large and small sized individuals of the 

 same se.x of a .species, that he had found by measurement of the horns of 

 •Lucanid stagbectles. The terms refer, however, not only to the horns but 

 also to the body itself, according to its strength. Bateson regrets "no suffi- 



[Trans. of Sapporo Natural History Soc. \'ol. IX, Part i. 1924.] 



