326 THE PHYSIOLOGY OF REPRODUCTION 



{Gryllus campestris), found that the castrated males chirped like normal 

 ones and mated with the females, and the spayed females behaved 

 like unoperated ones and bored holes in the ground although they 

 were unable to lay eggs in them. 



In spider crabs attacked by Sacculina the gonads disappear, and 

 in the total absence of the testis secondary sexual characters of the 

 female type are found in a large percentage of cases ; but this change 

 in the direction of the opposite sex may set in prior to the complete 

 disappearance of the testes. The change is manifested in the 

 appearance of the egg-bearing abdominal sac appendages, which have 

 no representatives in the male.^ Potts states that in the hermit crab 

 infected by a similar Pdtogaster, the modifications of the male which 

 occur are of the same type, and are maintained after the atrophy of 

 the testis, and cannot be necessarily consequent on the presence of a 

 secretion of the testis.^ 



In both these cases it would seem that the modifications which 

 take place are brought about independently by changes in the general 

 metabolism. This appears to be so also with so-called parasitic 

 castration in insects, for the gonads are not necessarily affected. 



In the male common shore crab it was found that the testis 

 underwent very little diminution after infection by Sacculina, but 

 that the male approximated to the female type. The change, 

 however, was less marked than in the cases referred to above, in 

 which parasitic castration was almost or quite complete.^ 



It would appear, therefore, that whereas many of the secondary 

 sexual characters are closely associated with the presence of the 

 genital glands, there are others which develop independently of any 

 influence from the organs of reproduction. 



Berthold seems to have been the first to put forward the view 

 that the testis is an organ of internal secretion which is responsible 

 for the development of the secondary sexual characters.* He based 

 his theory upon the results of testicular transplantation in fowls in 



1 Smith (Geoffrey), " Ehizocephala, Fauna and Flora of the Gulf of Naples," 

 Monograph xxix., Berlin, 1906. 



^ Potts, "The Modification of the Sexual Characters of the Hermit Cra,b; 

 caused by the Parasite Peltogaster," Quar. Jour. Micr. Science, vol. 1., 1906 ; and 

 "Some Phenomena Associated with Parasitism," Parasitology, vol. ii., 1909. 



^ Potts, "Observations on the Changes in the Common Shore Crab caused 

 by ScKculina," Proc. Camh. Phil. Soc, vol. xv., 1909. Upon recovery from 

 parasitic castration ova may be formed in what were "the testes. This has been 

 shown by Smith to happen with Inachus. Smith states that the parasite 

 Sacculina forces the crabs to elaborate a fatty or yolk material similar to that 

 which the normal female produces when the ovary is ripening. See also Smith's 

 "Studies in the Experimental Analysis of Sex," Qitar. Jour. Micr. Science, 

 vols. Ivi. and Ivii., 1910 and 1911. For the results of experimental or parasitic 

 castration in other Arthropods and groups of Invertebrates, see Lipschutz, loc. cit. 



* Berthold, "Transplantation der Hoden," Arch. f. Anat. u. Physiol., vol. 

 xlii., 1849. According to Berman {The Glands regulating Personality, New 

 York, 1921) the idea was advanced by Bordeu in the eighteenth century. 



