616 F. A. POTTS. 



served in infected testes (pi. 34, fig. 6, oi'o). Such evidence, 

 as far as it goes, seems to sliow that, as in the secondary 

 sexual characters, so in the primary, the eifect induced by 

 the parasite is a permanent oue, at least for a considerable 

 time, and does not pass away immediately with removal of 

 the primary cause. 



Eupagurus prideauxi. — In one (the unmodified) in- 

 fected specimen of this species testes of medium size were 

 found on dissection. The ducts exhibited the same pheno- 

 menon of excessive chitin secretion ; but while spermato- 

 genesis had entirely ceased, there was no appearance of egg 

 cells in the glandular part. The study of more material 

 might well, however, establish the existence of the pheno- 

 menon described above also in Eupagurus prideauxi. 



In concluding this account of the hermaphroditism of 

 Eupagurus, due to the action of the parasite Peltogaster, a 

 case of an apparently naturally occurring hermaphrodite 

 must be mentioned. This animal possessed typical female 

 appendages, but perfectly formed male apertures. On dis- 

 section, the gonad of the right side appeared completely and 

 normally male, though of somewhat reduced size; but on the 

 left side, though testis and duct were present, there were 

 large masses of mature brown ova. It is just possible that 

 this specimen was one which had recovered from parasitism 

 of Peltogaster, for we have seen above that the attachment 

 scar of the parasite may disappear with lapse of time, and if 

 complete absorption of the roots also supervenes no further 

 evidence of former infection remains. But this isolated case 

 cannot be cited as serious evidence of the capability of an 

 infected male to regenerate a complete hermaphrodite gonad. 

 I may, however, indicate the fact that the animal was pre- 

 dominantly male, possessing male ducts and apertures, 

 and gonads principally male; and since we have seen that 

 the effect of parasitism is to occasion the appearance of 

 ova in the testis, and alter the male secondary sexual 

 characters toward the female type, so we may imagine that 

 some other unknown cause, acting on a primarily male 



