HERMIT CRAB AND PELTOGASTER. 617 



organism at some unknown possibly embryonic period of 

 development, may produce a hermaphrodite of the character 

 described above. 



It will be interesting liere to briefly compare the pheno- 

 menon of hermaphroditism in the gonad of Inachus scorpio 

 caused by Sacculina neglecta, as described by Smith. 

 Here the testis of infected males, before completely atrophy- 

 ing, showed no appearance of ova. In those, however, from 

 Avhich the Sacculina was removed, and which regenerated 

 their testes, the externally modified and slightly modified 

 males show a completely male gonad ; the perfectly modified, 

 on the other hand, possess gonads with mature products of 

 both kinds. In the males of Inachus scorpio, then, the 

 capability of assuming the internally hermaphroditic state 

 would appear to be more restricted than in the crustacean 

 here considered. I am unable to say, however, whether the 

 male infected hermit crabs are able to regenerate a com- 

 pletely hermaphrodite gland in place of the testis on removal 

 of the parasite, as happens in Inachus. 



Many examples of infected and recovering ovaries were 

 likewise examined for evidence of hermaphroditism. But 

 though the cellular elements are so reduced in size from lack 

 of nourishment that many appear exactly similar to sperma- 

 tocytes, none of the stages of spermatogenesis were ever 

 seen, and in recovering ovaries the cells throughout increased 

 in size and recovered their ova-like appearance. 



COERELATION OF THE EFFECTS ON THE PeIMAEY AND 



Secondary Sexual Chaeactees. 



It was expected at first that some correspondence between 

 the degree of modification exhibited in the primary and 

 secondary sexual characters respectively might be traced, 

 but this does not appear to exist, and the development of 

 egg cells appears to take place in the same degree in 

 entirely unmodified animals as in those in which some 



