RESULTS OF CASTRATION 65 



hermaphrodite gland being found. But it may be that this is 

 caused by the different organs reacting in a different manner 

 under the conditions created by the parasite in the general meta- 

 bolism of the host. Discussing in the first edition of this 

 book the results of castration and heterosexual transplantation 

 in mammals (see especially Chapters IX. and XI.) I pointed 

 out that the differences one observes in these experimental 

 conditions in regard to the behaviour of the different parts of 

 the body can only be understood if we take into consideration 

 their different growth intensity, which seems to be a function 

 of time. In his remarkable investigation on the gipsy moth 

 Goldschmidt (1917, 1920) has shown that the different organs 

 change over to the opposite sex in different degrees ; he showed 

 further that those organs or parts of organs which normally 

 become differentiated very late turn to the opposite sex also 

 in slight degrees of intersexuality, as for instance the colouring 

 of the wings. On the contrary, organs which are normally 

 differentiated very early, change to the opposite sex only in 

 crossings with a very pronounced degree of intersexuality ; this 

 is especially true for the sexual glands which differentiate 

 cmbryologically very early, and which are found in different 

 stages of intersexuality only when all the somatic organs are 

 inverted. According to Goldschmidt time is a factor in the 

 degree of intersexualit}^ the latter being the more pronounced 

 the sooner the inversion to the opposite sex begins. We find 

 here in the crossing experiments of Goldschmidt an explanation 

 of the facts observed by Smith, Potts, and Courrier in parasitic 

 castration of crabs where many male somatic organs become 

 female without the testicle being destroyed or transformed into 

 an ovary or an hermaphrodite gland. 



Here again, as in the case of the moth, the possibility must 

 be taken into consideration that there is in the body of the 

 crab a special organ which controls the sexual characters 

 besides the sexual glands. No knowledge exists on this point, 

 but such a conception would not be in any way opposed to 

 Smith's hypothesis. 



It may also be mentioned that there are many other 

 examples of Crustacea in which one or more of the sexual 

 characters are sexually inverted to a greater or less extent 

 without interference by a parasite. For details Morgan s paper 

 (1920 b) may be referred to 



