780 



ON THE CH^TOSOMATID^, 



In the female, there are two ovaries lying in the ccelome below 

 the enteric canal, one behind, and one in front of the genital 

 aperture (PL xlv., a.ov., p.ov.). They are thick and short (about 

 0-066 mm. long), and the free end of each appears to be bent over 

 on the remainder. The portion of each furthest removed from 

 the genital pore, consists of finely granulated substance in whicli 

 a few, very large nuclei are scattered (Text-figs. 20-21, a.t'V.). The 

 remaining part is divided by distinct walls into large cells, each 

 containinof alar^e, round nucleus. These 

 are probably ova in process of formation. 

 The ovaries open into a single large 

 pp. uterus, which, in the adult, always seems 

 to contain numerous sperms. The genital 

 pore, by which it opens on the surface, 

 is a transverse slit, O'Ol mm. wide, situ- 

 ated on a slightly raised papilla. It 

 appears to be surrounded by very small 

 seta3, and has thick, chitinous walls. 

 p. pr^ ^\»^ Immediately below the aperture, lie two, 



^ ' thick, elongated cells, with very large 



nuclei, apparently enclosing the uterine 

 Embedded in the wall of the uterus, and 

 lying free in its cavity, are numerous rounded spots, stained 

 bright pink with eosin. 



In the male, the genital apparatus is in the form of a 

 straight tube, lying ventral to the alimentary c^nal, throughout 

 a greater part of the length of the trunk (PI. xliv.). It is dis- 

 tinctly divided into three portions. At the anterior end, 

 beginning 0-055 mm. from the neck, is the testis {t.), a narrow 

 cord consisting of a solid mass of granular matter not divided 

 into cells. Further back, cells become gradually differentiated, 

 and pass into a wide, tubular cavity, the vas deferens, where 

 they lie loose. At the level of the anterior end of the rows of 

 ventral setae, the vas deferens passes very abruptly into a narrow, 



Fig. 22.^^ 

 passage ( Text-fig. 2 2 



* L.S. through female genital aperture (a.), showing the large cells (2.) 

 surrounding the passage into the uterus; { x GIO); »p., sperms in uterus. 



