CONTRIBUTIONS TO THE ANATOMY OF EARTHWORMS, 4985 
points of difference from A. nove-zealandie; firstly, the 
entire absence of specially thickened septa. I have dissected a 
tolerably large specimen and compared it with a specimen of 
A. nove-zealandiz of about the same size; there was a 
very marked discrepancy in the relative thickness of some 
of the anterior septa; and this difference could not possibly 
be accounted for by the unequal size of the two individuals. 
The second anatomical différence between A. Rose and A. 
nove-zealandiz is in the form of the spermathece ; fig. 26, 
illustrates the four spermathecze, which, as is so common among 
Earthworms, have the most varied relations to the septa of the 
segments containing them, though the situation of the external 
aperture does not vary at all. Each spermatheca consists of a 
large pouch with relating thin walls; this communicates with 
the exterior by a short thick-walled muscular duct; this duct 
gives rise to a diverticulum which terminates in an enlarged cecal 
extremity, the surface of which is furrowed. The difference 
between the spemathece of this species and those of A. nove- 
zealandiz is that in the latter the diverticula are sessile (cf. 
figs. 24, 25). 
The Spermathece of Earthworms.—I believe that I 
was the first to direct attention to the fact that the diverticula 
of the spermathece in Acanthodrilus probably play a 
different part in the economy of the creature to the spermathecz 
themselves. In Acanthodrilus multiporus, in A. nove- 
zealandiz, and in A. dissimilis the spermathecal diver- 
ticula were always found—in the sexually mature individuals— 
to be crammed with spermatozoa ; while no spermatozoa could 
be discovered in the pouch itself.!| Dr. Horst had remarked 
before that in Pericheta sumatrana the diverticula of the 
spermathece were filled with an orange-coloured substance 
which appeared on microscopical investigation to be a mass of 
spermatozoa. He has more recently (25) found the same 
thing in Acanthodrilus Beddardi. I have found myself 
that in Pericheta Houlleti and in P. intermedia the 
* Dr. Rosa, however, in Acanthodrilus scioanus particularly states 
that spermatozoa occurred in the pouch as well as in the diverticulum. 
