On the generative Organs and Products of Tomopterii» unisciformis E. 431 



puscles were spermatozoa. Leuckart «fc Pagenstecher saw only 

 females. Huxley's example, obtained iu Torres Straits, was likely 

 a male, hut thouj^lt this is problematical , still , the size of the cells 

 seen in the body-cavity (^-j;^"' of an inch) agrees very closely 

 with the size of the heads of the spermatozoa in my specimens. 



Carpenter Ä: CLAPARi^i»E were the tirst to distinj^uish indubi- 

 tably individuals of the male sex, although they seem to have com- 

 jtletely misinterpreted the organs. Keferstein's suggestion that the 

 small groups of cells 0,016—0,02 mm, which he saw in individuals 

 with no egg-heaps, were "Samenzellen" must be received with caution. 

 Qi'atrefages distinguishes separate sexes, but gives no details indic- 

 ating whether he personally observed the differences or bases his 

 distinction on the diagnosis of Carpenter A: Claparede. Vejdovsky 

 and Greeff, as has been mentioned, distinguished separate sexes. 



The testes are found in the forks of all the parapodia with 

 well-developed bi-ramous divisions. Fig. 1 t. The generative tissue 

 originates from the endothelium of the fork. Fig. 4 en, and is easily 

 seen both in the living animal and in mounted specimens. Sections 

 prove that Brscn's statement, of epithelium being only present where 

 the sexual elements arise, is not consistent with the fact that endo- 

 thelial tissue clothes the whole of the inner surface of the body wall 

 and its appendages. The endothelium of the parapodium and of its 

 forks is continuous, but I have never found that genital cells arise 

 from the main-stem-eudothelium which is quite indistinguishable from 

 that of its two forks. The cells arise in both forks, and the organs 

 in neighbouring forks are always similar in size and shape. The 

 cells of the endothelium proliferate and the daughter-cells. Figs. 2, 

 3, 4 t. c, resulting stand forth from the wall. By successive multi- 

 plication the organ, from being a single layer of cells in thickness, 

 Fig. 2, gradually increases till a large portion of the lumen of the 

 fork is filled up with generative tissue. Fig. 1. This increase takes 

 place distally and proximally, as well as towards the centre of the 

 cavity. The whole mass of cells so originating constitutes the testes. 

 The appendages in which they are formed are truly lateral and forked, 

 but the succeeding appendages. Fig. 5 par , which are more or less 

 ventral and only indistinctly divided into two branches at the very 

 apex, do not bear testes. Carpenter k Clapar^de found what they 

 called "rudimentary ovaria" in mature males in the terminal walls of 

 the lateral appendages, but leave the determination to future obser- 

 vers of whether the cells of these develope into ova or remain rudi- 



