THE MICROSCOPE. 247 
Ayatomy or Cuiretiio.*—Beddard, having investigated the 
oligochetous worm clitellio, finds that the previous descriptions by 
Claparéde are, to an extent, both incomplete and incorrect. The 
testes in this genus, differing in no essential from those of  tubifex, 
lie in the tenth segment, into which open the funnels of the vasa 
deferentia. Each organ is long and narrow and somewhat swollen 
at the base of attachment to the body wall. Inthe generative system 
of a young example, of C. Arenarius, the cells of the vasa deferentia 
are not ciliated. The v. d. pass in a slightly sinuous course to the 
atrium, which opens externally, not far from the posterior border 
of the eleventh segment. The atrium in the undeveloped condition 
is lined by a simple non-glandular columnar epithelium. It is 
invested externally with a thin coat of muscles, outside of which is 
a tolerably thick layer of glandular peritoneal cells. The sperm- 
athecze are simple pyriform vesicles, lying in the tenth segment. 
Upon the anterior face of the septum, which separates the eleventh 
from the twelfth segment, and corresponding exactly in position 
to the funnel of the vasa deferentia, is a disc-shaped layer of 
columnar cells, which is evidently the oviduct, the cells of which, at 
this stage, are like the cells of the vasa deferentia funnels, not 
ciliated. In the sexually mature animal, the oviduct funnels are 
extremely conspicuous cell-shaped organs with abundant cilia. 
The ovaries are situated in the eleventh segment on the anterior 
mesentery, close to where this is perforated by the vasa deferentia. 
The sexual organs in C. Ater. and C. Arenarius differ somewhat. 
In C. Ater. there is a distinct and large prostate gland, which opens 
into the distal extremity of the glandular part of the atrium. In 
C. Arenarius these glands seem to be absent. The glandular part 
of the atrium in the latter is relatively larger than that portion of 
the former. The glandular portion of the atrium, although exhibit- 
ing the same structure, is. relatively smaller than that of C. Arenari- 
us, and is entirely contained within the eleventh segment, and is 
not curved upon itself. The vas deferens is very long and much 
coiled. It opens into a rounded chamber at the extremity of the 
atrium, the cells of which are different from those of the atrium 
and more like those of the vas deferens. In C. Arenarius the vas 
deferens is much shorter and wider, while the atrium is much 
larger ; on one side of the body, in the single mature example of 
this species investigated by sections, the atrium was bent upon itself 
and entirely contained in the eleventh segment. On the other side 
of the body the atrium extended back beyond this segment. The 
* Proc. Zool. Soc. London, Noy. and Dec., 1888, p. 485. 
