260 E. S. GOODEICH. 



with granular protoplasmic contents. Under this is a thin 

 layer of circular and a few longitudinal muscles (c. m.), 

 followed by the ciliated lining epithelium of the duct {w. of 

 sp.) composed of small granular cells. In the narrow region 

 of the sperm-duct the coelomic epithelium is not modified 

 (fig. 18, c. ep.), while the lumen is bounded by columnar 

 epithelium, the cells of which are very deep when the duct is 

 not expanded (fig. 18, w. of sp.). There is no special penial 

 apparatus, and no prostate. 



The oviducts appear to be reduced to a mere depression on 

 each side of the ventral edge of the 12th septum (fig. 

 12, ovd.). 



The spermathecse are two pear-shaped sacs (fig. 12, spth.), 

 opening in the median ventral line by means of a common 

 median pore immediately below the nerve-cord at the an- 

 terior end of the 10th segment (fig. 2, splh. p.). Fig. 20 

 shows a transverse section of an adult worm in this region 

 passing through the median pore [spth. p.), at which open 

 both the right and the left spermathecse (spth.). It is interesting 

 to note that in the young worm a similar transverse section 

 (fig. 21) shows that here the two spermathecse (which have all 

 the appearance of being direct invaginations of the epidermis) 

 arise distinctly from right and left points some distance from 

 each other (fig. 21, spth.p.) ; it is only later that the necks 

 of the two organs approximate and finally open by a 

 common aperture. This may easily be confirmed by surface 

 views of the living worm. The structure of the wall of mature 

 spermathecse is shown in fig. 19. Outside is the ordinary 

 coelomic epithelium (c. ep.), followed by a layer of scattered 

 longitudinal and circular muscles ; finally we have lining the 

 interior of the organ a thick epithelium, with large oval nuclei 

 ranged with their long axis parallel to the surface. The lumen 

 of the neck of the spermathecse has a pronounced constriction 

 and enlargement (fig. 12), as in many Tubificidse. Spermato- 

 phores have not been observed. 



In the mature worm there are two large sperm-sacs and one 

 large ovisac. By cutting longitudinal sections of individuals 



