334 J. E. BLOMFIELD. 



stance of the spermatoblast. Further researcl)es on this point 

 are needed, especially with reference to the constitution of a 

 nucleus disclosed by the researches of Flemming. 



These remarks would be incomplete witliout reference to the 

 observations of M. Sabatier, who in ' Comptes rendus,' 94? 

 1882, pp. 172-3, has recorded his observations on Spermato- 

 genesis in Salmacina (one of the Serpulida?). In this worm he 

 finds that a spermatospore or mother cell becomes covered by 

 multiplication and budding of nuclei with a mass of clavate 

 cells (protospermatoblasts) which do not themselves give rise 

 to spermatozoa, but become detached, and then, by nuclear 

 multiplication and budding, produce a crop of spermatoblasts 

 (deutospermatoblasts), from which the spermatozoa originate. 

 He uses these observations to explain the process of the forma- 

 tion of testicular ampullae in the lower Vertebrates, and to com- 

 plete its comparison with the formation of a Graaffian follicle, 

 as suggested by Balbiani. 



According to this latter observer an ampulla is formed by 

 a central cell surrounded by smaller ones. The central cell 

 represents the female part, and takes no share in the formation 

 of spermatozoa, while the smaller ones represent the male part 

 of the primordial indifferent cells. This state of things is 

 reversed in the Graaffian follicle of the ovary, in which the 

 central cell (the female portion) undergoes development at the 

 expense of the surrounding epithelial cells of the follicle 

 representing the male element. This central cell of the am- 

 pulla could, on M. Sabatier's view, be represented by the sper- 

 matospore, the cells lining the ampulla would be the proto- 

 spermatoblasts, and the cells which we have called spermato- 

 blasts would be deutospermatoblasts. 



While this paper was being written a notice appeared in 

 the ' Zoologische Anzeiger ' for the 19th Feb., 1883, referring to 

 researches made by Max v. Brunn on the double form of sper- 

 matozoon found in Paludina, to which, in conclusion, I must 

 make a brief reference. He finds that the formation of the 

 head does not take place endogenously and without the nucleus, 

 as stated by M, Duval, but that it is produced as described by 



