234 



DR. W. B. BENHAM ON 



[Nov. 15, 



RejyroduGiive system. — There are two pairs of large, botryoidal 

 sperm-sacs in segments 11 and 12, attached, of course, to the 

 anterioi- wall of these segments. 



The prostate (text-fig. 50, p. 233) is tongue-shaped, long, more 

 or less convoluted, with apex recurved ; it extends through 

 segments 17 to 21 ; its muscular duct is confined to segment 17 ; 

 it is rather long, but very narrow where it leaves the gland, 

 dilating to form a thicker, pear-shaped bulb as it penetrates the 

 body-Avall. 



Ai'cuate muscles are developed in segment 17, 



Associated with each prostate are two sacs containing each two 

 penial cheetfe, a long functional and a shorter reserve bristle. 



Each penial chasta (text-figs. 51, 52, p. 233) is stout, nearly 

 straight, and, compared with the size of tlae worm, not very long : 

 it terminates in a rounded knob, which carries at its end a shoi-t, 

 stout, curved, blunt hook. There are no markings at this end ; 

 but about midway along its length there is a series of rather 

 closely-set, irregularly aiu^anged, short, oblique, and finely serrated 

 ridges. 



The relations of the various parts of the male ducts, as studied 



Text-fig. 53. 



Text-fiff. 54. 



l( ift] \ 



\ 



\ 



Text-fig. 53. SJiododrilus ; et^MZis.— Diagrammatic sketch of a section through the 

 porophore, showing the openings of the sperm-duct (S.P.), prostate duct (P.R. ), 

 and the penial cha3ta3 (P.CH.) into a small antrum or chamber, which communi- 

 cates with the exterior at the apex of the papilla (<?). The sketch is compiled 

 from a series of sections, and the above pores are not, in reality, in one plane — 

 the prostate pore being most anterior, and the sperm-pore most posterior of the 

 three. V. is the ventral side. L. is laterallj' placed. 



Text-fig. 54. Mliododrilus edulis. — Spermatheca (X4). The main sac, or ampulla, 

 opens externally, independentlj' of the diverticulum (D. W.). 



in sections, is as follows (text-fig. 53) .• — at the apex of the poro- 

 phore is a small pore, which leads into a shallow, but laterally 

 extended chamber, the floor of which rises up as a papilla. At 



