RESULTS OF CASTRATION 57 



sexual gland from a quantitative point of view. But this 

 objection is scarcely valid against the conclusions of Meisen- 

 heimer and Kopec, as they carefully examined the internal organs 

 of their experimental animals . The same ob j ec tion was made by 

 Kammerer to the experiments of Regen on crickets.' The grubs 

 developed into animals with fully developed sexual characters. 

 Still a third objection remains to be considered, and this is 

 one which was pointed out by Kammerer, and which might 

 be much more weighty than the previous ones if it were based 

 on definite facts. The zoologists who experimented on moths 

 have described certain somatic changes after castration. One 

 might be tempted to explain these changes which do occur 

 as due to a lack of a specific influence on the part of the sexual 

 glands. In Lymantria dispar castrated by Meisenheimer, 

 there were changes in different parts of the internal sexual 

 apparatus such as the oviduct, the receptaculum seminis, and 

 the vas deferens. It is, however, impossible to conclude 

 from these changes that the formation of the respective organs 

 is influenced in a specific manner by the sexual glands. These 

 changes do not occur constantly. Kopec found further that 

 the}^ are present after unilateral castration only on the operated 

 side. Kopec explains all these changes as due to the modified 

 mechanical relations after castration. According to Kopec 

 this is particularly clear in the female, in which a good deal of 

 space is set free in the abdomen by the removal of the ovaries. 

 Lesions of the internal sex-apparatus, made during the opera- 

 tion, may also be of importance. Meisenheimer found further 

 changes in the colouring of the wings after castration. A 

 darkening of the wings which are normally white could often 

 be observed in castrated females of Lymantria dispar. In the 

 castrated males the wings, which are normally dark, became 

 lighter. Meisenheimer, however, could bring about this 

 change in the wings of the male by starving the normal 

 caterpillar. These pecuharities of the wing colouring, therefore, 

 are to be explained as due to external factors. Kopec came 

 to the same conclusion. After all there can be no doubt that 

 in moths the sexual characters are by no means dependent 

 upon the sexual glands. The external appearance, the internal 

 and external sex-apparatus, the regenerating wings and 

 antennae, and the psycho-sexual behaviour are not influenced 

 in their formation by the sexual glands. 



