RESULTS OF CASTRATION 55 



having been removed) 16 developed normal colouring. Like- 

 wise out of 18 normal control animals kept under the same 

 external conditions, 16 developed normal colouring. In a 

 series operated upon in March, there was no nuptial colouring 

 either in the castrated, or in the partially castrated and 

 control animals; Kopec explains the failure of this series by 

 the assumption that in these animals caught so early, the 

 gonads did not attain maturity in confinement. That 

 some castrated animals of the April and March series exhibited 

 nuptial colour, may be due according to Kopec to the fact that 

 at time of catching there was already a beginning of nuptial 

 colouring, or, in other words, that at that time the gonads were 

 already more or less developed physiologically. There can be 

 scarcely any doubt that nuptial colouring in fishes depends 

 upon the sex glands. 



E. THE RESULTS OF CASTRATION IN ARTHROPODA. 



I. Moths. ^ 



Castration experiments in moths have been made by 

 Oudemans, Kellogg, Meisenheimer and Kopec on Lymantria 

 dispaVf the silk-moth (Bombyx mori) and other species in 

 which the sexual dimorphism is well marked. Both cater- 

 pillars and moths were castrated; the sexual glands were 

 removed with scissors or burned out with a hot needle or a 

 galvanocautery such as is used for medical purposes. 



All the investigators agree that the formation and persist- 

 ence of the sexual characters in moths are quite independent 

 of the sexual glands. The internal and external copulatory 

 organs developed normally in "castrates," although the differ- 

 entiation of the copulatory apparatus and of the excretory 

 ducts occurred long after the operation {Meisenheimer). The 

 colour, size and form of the wings were normal, even when 

 the caterpillars were castrated immediately after the first 

 desquamation. If together with the sexual glands the wing 

 rudiments on one side are removed, as was done by Meisen- 

 heimer, a more or less complete regeneration of the wings 

 occurs. The regenerated wings are of the normal appearance, 



^ Kope6y 1912; Meisenheimer^ 1909; Harms, 1914, pp. 139-155; Kammerer^ 

 1912, pp. 109-115. 



