74 ME. p. E. BEDDAED ON THE ANATOMY AND 



rather different; there is no such regularity in its arrangement, and the cells are 

 aggregated into variously sized groups ; this appearance is displayed in fig. 8 of PL XV. 

 Whether these aggregations of cells are really independent glands or not I am unable 

 to state; it is sufficiently evident, hovi'ever, that the clitellum of Microchwta does differ 

 from that of Lumlricus, and I hope to be able to study it more fully at some futuj-e 

 time. The description here is of preparations which have been only hardened in strong 

 alcohol ; this reagent appears to preserve the structure of the hypodermic cells very 

 well indeed, but as I have not been able to compare its effects on the glandular region 

 of the clitellum with that of other reagents, I am rather afraid of going into any more 

 detailed description of the clitellum, and possibly describing the effects of the reagent 

 instead of the real structure of the cells. 



The glandular portion of the clitellum is extremely vascular, and sends off here and 

 there a loop of capillaries which penetrate the hypoderm as in other Earthworms. 



(2) The testes ^ (PI. XV. fig. 14, t) are two pairs of oval somewhat flattened glands, 

 situated in segments ten and eleven; the anterior pair are rather larger than the 

 posterior ; both are enveloped in a membranous sac, and are also firmly attached to the 

 proximal portion of the vas deferens. The testes harbour an immense number of 

 Gregarines. These parasites are constantly found in Earthworms. 



(3J The vasa deferentia (PI. XV. fig. 4, vd) are two delicate tubes, slightly sinuous, 

 which open into the exterior of the body in the eighteenth segment just to the inside 

 of the opening of the segmental tubes ; at its point of aperture the vas deferens of 

 either side is slightly dilated, but there were no traces of any prostate glands such as are 

 so generally met with in Earthworms, especially in the postclitellian and intraclitellian 

 genera. The position of these orifices within the clitellum shows that Microchmta must 

 be referred to the Lomhriciens intraclitelliens of Perrier. The vasa deferentia are rather 

 hard to follow ; their diameter is almost exactly the same as that of the longitudinal 

 muscle-bundles, and moreover in segment sixteen they appear to run within the latter ; 

 at any rate I was unable to see them in this segment, though they were, comparatively 

 speaking, obvious in the preceding and the succeeding segment. In the twelfth segment 

 the vas deferens bends inwards towards the middle line of the body and approaches its 

 fellow of the opposite side ; it perforates the mesentery and blends with a long, some- 

 what oval, solid-looking body lying beneath the testes of its own side, and almost in 

 contact with the corresponding structure of the other side of the body. This structure 

 represents the ciliated funnel of the vas deferens, which is, in this Earthworm, extremely 

 complicated ; instead of opening freely into the body-cavity its aperture appeared to be 

 plugged by the testes, to which it was firmly attached by its posterior extremity ; a 

 transverse section showed that this structure does really represent the fimbriated 

 aperture of the vas deferens. It contains numerous cavities lined by tall, columnar, 

 ciliated cells, and its compact structure is due to an excessive complication of the folds 

 • Probably the equivalents of the seminal vesicles of Lumlricus and not the true testes. 



