78 a i!"j— jft if> A /J ©• y.;. </> ^ th $ ri<j »f -^ 



cicat miinljcr i 'f male sia;4l)cctlcs has yet I)ceri received to warrant any state- 

 nient as to freiiueiuy of tlie various tjpes of male." Now the Lucanid 

 .stagbeetles are, however, very cuinnion in fcjrest localities in this country. 



The staj^'beetles occur \er)' abumlantly in our uni\er.sity grounds, being 

 reijrcsentetl by two species calletl resjiectively Cladognatlms inclinatus, Motsch; 

 aiul Lucivius iitaatlifiiiti'ratus, Molsch. During the last lew }-ears (1917-1919), 

 a numlaer of s[iecinicns was collected chietl)' by Dr. Ycsliimaro Tanaka. As 

 is very well known, the male beetles are built very strongly and carry a pair 

 of si)lentlid antlers which are nothing else than \igorous mandibles. The 

 females are fLu-nishcd wiiii a [»air of solid but .short jaws. Accordingly, these 

 features of both sexes afford us already an excellent example of .se.xual di- 

 muri)hism; but this is not the <inly tlitference. Upon further examination we 

 tind that there arc in these forms other features which show the facts of 

 variation. 



Last spring, I had an o[)portunity to study the above mentioned collec- 

 tion which consists of 1362 males and 1333 females of Cladognat/ms and 320 

 males and S09 females of I.iicauus. In specimens, taken at random, measure- 

 ments anil examinations of se\-eral facts ha\e been carried out. and we find 

 that the law of 'high' anil 'low' individuals quite obviously applies to them. 

 As the body Itiigth I have taken the extent from the top of the caput to the 

 hind extrcmit)' of the sheathwings. 



In this place, I wish to expiess my thanks to Dr. Hatta for his courtesy 

 shown during my present stud)-. I am also very much indebted to Dr. Tana- 

 ka who allowed me the free use of the collection. 



I. Cladognathus inclinatus, Motsch. 



Mali'- — The de\eIopment of the mandibles in strength and otherwise, may 

 be sail! to be ]iroportional to the bod\-build: a large sized 'high' form is built 

 solid and carries, together with strong legs, arched and \igorous antlers with 

 several strong tines (I<"ig- I, <?-<"), while the small 'low' forms have straight 

 short antlers looking like a pair of scissors with serrated edges, gi\ing a 



