568 WILLIAM BLAXLAND BENHAM. 



find at first, but my dissectious are confirmed by transverse 

 sections. 



Close behind each testis is a ciliated rosette, lying, 

 therefore, in somites x and xi, and close to the posterior 

 septum of the somite. (Orley wrongly states that they are 

 attached to the anterior septum of somites xi and xii, into 

 which they project.) 



The sperm-ducts from the two ciliated rosettes of one side 

 unite at the level of the septum behind somite xi, and the 

 single duct passes to somite xv, embedded in the connective 

 tissue which exists between the coelomic epithelium and the 

 longitudinal muscles of the body wall ; hence it is practically 

 impossible to trace it except by means of sections, unless it 

 happen to be filled with spermatozoa, when it will appear 

 whiter than the surrounding tissue. In somite xv is a large 

 and conspicuous hemispherical gland, which may be called a 

 prostate ; the sperm-duct passes to the dorsal surface of this 

 gland, dips down through its mass and opens to the exterior by 

 the pore mentioned above, which is situated on a prominent 

 rounded papilla, which seems to be merely the outer half of 

 the prostate. This gland itself consists of cells similar to 

 those forming the epidermis of the cliteilum, and quite con- 

 tinuous with them ; the muscular layers of the body wall are 

 here thin, and pass over the inner surface of the prostate, so 

 that the gland appears to be formed merely by an hemispherical 

 thickening of the epidermis over this area. 



The ovary is a flattened rounded disc attached to the 

 anterior septum of somite xiii, close to the nerve cord (fig. 15, 

 f). It resembles the ovary of Perichseta in shape, and is 

 without the tail-like prolongation of the ovary of Lumbricus 

 (fig. 19). It is figured in Vejdovsky^s work,^ but I have added 

 a figure here, as he does not show the delicate membrane sur- 

 rounding the organ. 



The ovisac (which seems to be a better name than Bergh's 

 '^receptaculum ovorum/' since the word '^ receptaculum " 

 has been applied to a spermatheca) is a botryoidal sac-like 

 ' Loc. cif., pi. xiii, fig. 23. 



