NOTES ON THE EREE-LIVING NEMATODES. 447 



In the Cirri pedes we have anotlier clear case of the successful 

 establishment of hermaphroditism in a group in which the 

 sexes were originally separate. Here^ too, in hermaphrodite 

 species there is a survival of the male sex, but the individuals 

 which represent it are so degenerate in form and structure as 

 to be described as little more than a bag of spermatozoa, and 

 so reduced in size as to well merit the title of "dwarf 

 males.' ^ 



It is, however, a surprising fact that in no particular of 

 structural organisation do the males of hermaphrodite species 

 appear to fall behind those of bisexual nematodes. The 

 conclusions which Maupas reached on this subjects are summed 

 up in the following quotation : 



" Ces males . . . n'offront rien de particulier et 

 d'anormal. On ne remarque rien dans leur structure et dans 

 leur organisation generale qui puisse ies faire considerer 

 comme des animaux mal venus on mal constitues. Par leur 

 taille, par Ies proportions de leur corps et par tons Ies details 

 de leur organisation, ils repondent de tons points au type 

 male ordinaire des Rhabditides dioique. Leur testicule 

 luimeuie est constitue d'une f;i^on absolumeut norujule et, 

 ses produits, Ies spermatozoides, sont palreur forme, leur 

 volume et leur structure absolumeut identiques ;i ceux que la 

 glande genitale des femelles produit pendant sa periode 

 d'activite proterandrique." 



My own observations show that there is no imperfection of 

 development in the residual males of such species as I was 

 able to study. The spermatozoa were always pi-oduced in 

 vast quantities and exactly like those formed liy the 

 hei-maphrodites. When liberated by pressure from the body 

 oF the male, they could be observed to put out amoeboid 

 processes like those which Ziegler figures taking up their 

 position in the uterus of Diplogaster longicauda after 

 fertilisation. This observation tends to show that the 

 spermatozoa are physiologically active though the individual 

 which carries them is prevented from playing its part in 

 reproduction, possibly by a defect in nervous oi-ganisati^m. 



