OCR Text |
Show 354 MR. F. E. BEDDARD ON EARTHWORMS [Apr. 16, without windings, opens into the spermathecal sac above the alimentary canal, just at the point where the two sacs surrounding the gut coalesce. The mode of its opening is, however, important for description. The duct, I may say in the first place, has a minute structure which is very similar to that of the part of the oviduct which runs from the funnel to the exterior. It is ciliated Text-fig. 87. Semidiagraminatic representation of the female generative system of Stuhlmannia. X 6. be, bursa copulatrix; ds, dorsal prolongation of spermathecal sac; ms, median region of the same; o, ovary ; od, oviduct; p, oviducal pore ; sp.p, spermathecal pore : X , cut end of spermathecal sac. for a short way below, but higher up appears to lose its cilia. It is lined, however, with cubical cells, and has a thickish muscular wall. The sac into which it opens is of a very different nature: the cells which line it are tall and glandular-looking; it is thus easy to demarcate the orifice of the tube where it opens into the sac. At this point the lower epithelium of the duct is spread out for a short distance round its actual orifice iu a fashion quite reminiscent of the funnel of some of the lower Oligochaeta ; more than this, the cells were ciliated in this region. As to tho ciliation as a criterion of the oviducal nature of the duct, it is apparently not necessary to insist upon it. Eisen distinctly states that the oviduct, the undoubted oviduct of Eudrilus, is not ciliated ; and llorst did not fiud cilia everywhere. N o w it must be borne in mind that the sacs of the spermathecal apparatus belong to the xiiith segment. Their enormous development causes a growth backwards ; but nevertheless the orifice of the mouth of the tube must be placed in the xiiith segment. I canuot iu fact explain the structure of this part of the egg-couducting apparatus except on tbe view that we must look upon the tubes |