228 (IKOFFREY SMITH. 



endopodite, now a slender-jointed structure, being fuinished 

 with exceedingly long pointed, hairs for tlie attachment of 

 the egg^. The structure of these abdominal appendages in 

 tlie adult female, adapted as they evidently are for repro- 

 ductive purposes, is as morphologically distinct from that of 

 the young individuals of either sex as anything very well 

 could be. 



Now let us inquire in what form the infected modified 

 males assume the abdominal appendages. The answer is 

 plainly given by reference to PI. 14, fig. 4. This ligure is an 

 actual camera drawing of the second abdominal appendage of 

 an infected individual, which was proved to be a male by the 

 presence of a copuhitory style of a somewhat modified form 

 (PI. 14, fig. 3), and inteinally by the presence of testes and 

 vesicuke seminales of a typical character on either side. The 

 testis and vesicula seniinalis of one side of this individual are 

 shown in PI. 14, fig. 10. The form of the abdominal ap- 

 pendfiges (PI. 14, fig. 4), of which there were four on each 

 side in addition to the copulatory styles, is identical with that 

 of a normal adult female; in fact, since this figure serves 

 equally well to depict the abdominal appendage of a normal 

 adult female, I have not considered it necessai-y to give 

 another figure, which would simply mean repeating the same 

 structures. 



The infected male individual to which figs. 3, 4, and 10 on 

 PI. 14 refer is a particularly favourable type for showing con- 

 clusively that the abdominal appendages, when assuined by 

 the infected males, are of the characteristically adult female 

 type. As a matter of fact a commoner condition is that shown 

 in PI. 14, fig. 5. In this infected male the copulatory 

 style was greatly reduced (fig. 6) and the abdominal appen- 

 dages were also developed in an imperfect condition, with 

 almost complete suppression of the endopodites. Neverthe- 

 less, the characteristic plumose hairs are present on the exo- 

 podite, Avhich is of a slender shape, thus conforming to the 

 adult type of female appendage and not really approaching to 

 the juvenile condition. This figure might equally well reler 



