428 J- H. FULLARTOK, 



in the caudal prolongation as testes, and say that each testis consists 

 of ''an undivided sac, whose cavity, when the organ has attained its 

 maturity, is almost entirely filled with a mass of spermatozoa", and 

 the individual spermatozoa are kept in motion "by the action of the 

 cilia clothing that part of the inner wall of the testis which is near 

 its external orifice''. They describe and figure two orifices, one at 

 the posterior or distal end leading to the outside, and the other on 

 the inner and anterior side, which is occasionally seen, opens into the 

 body-cavity. They state that the external orifice is distinct from 

 "the large ridged rosette of the ciliated canal", but are not sure of 

 its distinctness from the smaller rosette. The spermatozoa, which 

 they figure, have two tails like the antherozoids of Algae. The 

 testes are said to occupy the same position in the lateral appendages 

 that the ovary does, the chief difference being in the size of the 

 appendage, but Cakpentek & Claparîîde mistake the oval vesicles 

 for testes. Even if they were testes , situated at the base of the 

 appendages as they are, they can scarcely be said to be in the same 

 or a corresponding position to the ovaries, which are at the apical 

 terminations. They corroborate Leuckart & Pagenstecher's obser- 

 vations on the place of origin of the ovarian cells in the lateral 

 appendages, but add that "they are developed also in the caudal 

 prolongation". "Their rudimentary ovaria", alleged to occur in mature 

 males in the lateral appendages, are probably the tissue which gives 

 rise to spermatozoa. Their view as to what are testes, when we 

 come to deal with the structures shown in sections of the parapodia 

 and of the ovoidal vesicles, will be further dealt with. They failed 

 to find any female genital orifice. 



Gkgenbaur ') in his Comparative Anatomy, in describing the 

 generative organs of Annelids, figures ovarian cells in Tomopteris as 

 arising in one of the forks of the parapodium. 



Kefer.stein -) made investigations on Tomopteris taken from 

 Sicilian waters, and like Carpenter & Claparède failed to notice 

 what Leuckart & Pagenstecher had seen, a female genital orifice 

 to the exterior. Like previous observers he perceived the seat of 

 origin of the eggs, but while he denies the presence of a lining layer 



onisciformis Escn., in : Trans. Linn. Soc. London, V. 23, p. 69, tab. 7, 

 fig. 1—14. 



1) Gegenback, Grundri.s8 der vergleichenden Anatomie. 



2) Kefekstein, Einige Bemerkungen über Tomopteris, in : Archiv 

 f. Anat. u. Physiol., Jahrg. l«Ül, p. iJCO, tab. !», fig. 1-6, 9. 



