372 W. BLAXLAND BENHAM. 



of the cell. But I can give no detailed description of the 

 finer histology owing to the ill-preservation of my material; I 

 can detect granules, as if arranged around vacuoles, but very 

 indistinctly. Outside the glands is a very delicate membrane 

 {coe. ep.), sparsely provided with flattened nuclei {n, per.), 

 which I take to be the coelomic epithelium, and which dips 

 down, for some distance at any rate, between the groups of 

 cells. 



In Beddard^s figure the muscular coat is made to be con- 

 tinuous, and no indication of " ducts '^ or communication 

 between the gland-cells and the lumen is represented, though, 

 as the above quotation shows, Beddard expected to find such 

 "ducts." My description of M. indicus agrees pretty 

 closely with Rosa's description of the prostate of M. Bed- 

 dardii, and figure relating to the prostate of Desraogaster. 



Beddard has already (4, p. 125) pointed out the resemblance 

 between the gland (cement-driise, prostate) attached to the 

 atrium of Tubificidse and the glandular lining of the atrium 

 of Perichseta and other earthworms; at the same time he 

 has denied the homology of the gland-cells of Moniligaster 

 with those of Acanthodrilus, Perichaeta, and other worms, 

 chiefly, if not entirely, on the ground that in Moniligaster 

 and in Rhynchelmis there is (according to his observations) 

 no peritoneal membrane surrounding the glands ; whilst the 

 position of the gland-cells outside the muscular coat led him 

 to regard these cells as representing the peritoneal membrane. 

 Bnt I have seen what I believe to be the peritoneal membrane 

 both in M. indicus and in Rhynchelmis; and further, the 

 prolongation of the extra-muscular gland-cells up to the epi- 

 thelium of the atrium in Moniligaster and Desraogaster 

 seems to me to point conclusively to the derivation of those 

 gland-cells from that epithelium, in the same way that the 

 "cement-driise" of Tubificidse has been shown by Vej- 

 dovsky to be developed as an outgrowth from the lining of the 

 atrium. Therefore probably the "prostate" of Tubifex is 

 homologous with the "prostate" (using the word in a narrow 

 sense to mean the glandular cells) of Moniligaster. 



