1886.] LITTLE-KNOWN EARTHWORMS. 307 



find no traces whatever of ova in the former body, and its walls were 

 comparatively thick and composed of muscular or perhaps connec- 

 tive-tissue fibres. These two series of facts are very decidedly 

 opposed to the view that this body is really the ovary, and I have 

 no doubt whatever that it corresponds to the receptaculum ovorum. 

 In Lumbricus the receptaculum ovorum was correctly described by 

 Hering, as Bergh has pointed out. More recently the structure 

 has been figured by Dr. Horst*, who also quotes Bering's observa- 

 tions. I have myself observed an evidently similar structure attached 

 to the oviduct of Acantkodrilus dissimilis. Dr. Bergh describes the 

 origin of these bodies as being similar to that of the receptacula 

 seminis ; they arise on the anterior wall of segment 13, and are at 

 first iudependent of the oviducal funnels but subsequently unite 

 with them. In MicrochcBta these receptacula ovorum appear 

 therefore more completely to retain their primitive position. It was 

 obvious, however, from my sections that there was a communication 

 through the mesentery between the receptacula and the oviduct. 

 The identification of the supposed ovaries with the receptacula 

 ovorum confirms so far the accuracy of my own determination of the 

 oviducal funnel. I am bound to say, however, that a most searching 

 examination of my sections failed to bring to light any traces of the 

 oviducal canal. I see that Mr. Benham has also failed to detect 

 any connection between the funnel and the exterior. Assuming, at 

 least for the present, that the supposed ovary is nothing more than a 

 receptaculum ovorum, the true ovary remains to be identified. This 

 I believe to be a glandular-looking body in segment 12, noted 

 by Mr. Benham but overlooked by myself at the time when my 

 paper was written. Mr. Benham describes and figures {loc. cit. 

 pi. xvi. fig. 8) this gland as consisting of a " mass of rounded cells 

 arranged in a band which is bent upon itself several times, the folds 

 being close to one another." It is attached to the anterior septum 

 of somite 12. In the specimen of this worm more recently dissected 

 by myself, I have found a structure which must correspond to that 

 described by Mr. Benham, though it occupies a slightly different 

 position and is somewhat different in structure. This gland in my 

 specimen was elongated and composed of a mass of rounded in- 

 different cells ; the anterior end of the gland was wider than the 

 posterior extremity, which tapered gradually, and was attached to 

 the anterior mesentery of segment 12 ; the main part of the gland 

 lay along the ventral body-wall close to the nerve-cord. 



The reasons which lead me to suppose that this cellular mass 

 represents an ovary in a state of functional inactivity are- — first, 

 that it occupies the right position ; secondly, that it corresponds 

 exactly in structure to certain glandular bodies in Acantkodrilus 

 dissimilis^, in which I have observed the occasional development of 

 ova. 



' Tijclschr. cl. Nederl. Dierk. Vereen. Deel iii. afl. i. p. 28. 



2 P.Z.S. 1885, p. 828, pi. Iii. fig. 9. 



