88 



Lankester's account is confirmed by Conté and Vanev, but the testis is said to be "une 

 différentiation de Textrémité antérieure du pédoncule", the axial part of which gives rise to the 

 testis. It is not quite clear what is the precise meaning of this passage, taken in conjunction 

 with the statement that Lankester's account is correct; nor do I profess to understand the 

 short description given by the same observers of the ovary of Rhabdopleitra. But what is said 

 of the testis may perhaps indicate that this organ is developed at the anterior end of the 

 metasome (as in C. sibogae) before that part shews any différentiation into body and stalk. 



It is hardly necessary for me to criticize Conté and Vaney's account of the general 

 morphology of Rhabdopleura, and I may merely refer to the remarks made by Fowler (04) 

 on the subject. But I think there can be no reasonable doubt that Rhabdopleura is really 

 related to Cephalodiscus, and the denial by Conté and Vaney of the presence in Rhabdopleura 

 of such organs as the collar-pores or of subdivisions of the bodycavity are directly controverted 

 by the careful work of Fowler (92, i , 2 ; 04) and Schepotieff (04), as well as by the few 

 observations I have been able to make on the same subject. 



\\\ the case of the zooid of C. sibogae shewn in fig. 3, there is some evidence of the 

 existence of a single, posteriorly situated testis ^ similar to the organ described by Lankester 

 in Rhabdopleura; while in the specimen to which the abnormal arm shewn in fig. 98 belongs 

 there appear to be two testes situated in the third body-cavity, in the position of the ovaries 

 of a female Cephalodisciis. I do not feel quite confident of the accuracy of these observations, 

 but it does not seem to me impossible that one of the individuals which is normally neuter may 

 exceptionally develop a testis. If this is really the case, it appears to imply that the vestigial 

 cfonads of the neuter are to be regarded as testes, and the neuters themselves as males with 

 suppressed gonads. But this conclusion rests on too slight a basis to be worth much. I need 

 hardly say that I have no evidence that an^thing like protogynous hermaphroditism occurs in 

 Cephalodiscus, as is believed by Conté and Vaney to be the case in Rhabdopleura. 



Two que.stions relating to the physiology of the male will at once occur to any one 

 conversant with the facts; — namely (I) the mode of nutrition, and (II) the function of the 

 curious vesicles of the epidermis of the arms. 



(I) Nutrition of the male. 



It has just been shewn that the alimentary canal of the male is a vestigial structure. 

 There is no tracé of a glandular stomach ; and moreover the arms are not provided with 

 tentacles, and there is no recognisable operculum. Vcstiges of food-grooves can, however, be 

 distinguished in section at the bases of the arms, which in other parts are circular in section. 



The male has on the contrary a well developed vascular system ; and it appears to me 

 that this is the direction in which one must look for the solution of the que.stion indicated. The 

 males are probably nourished by the neuter individuals, through the medium of the vascular 

 system, in a manner analogous to that in which the nutriment absorbed by one set of individuals 

 in Doliolum is said to be transferred through the vascular system of the asexual form to an 

 entirely different set of individuals. 



l) This is not shewn in the figuie, which represents an anteriov view. 



