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Show 340 MR. F. E. BEDDARD ON EARTHWORMS [Apr. 16, The median part of the spermathecal sac is traversed by two longitudinal blood-vessels, of which one is the ventral blood-vessel and the other a special branch for this part of the body; the two give off branches laterally and have the relations of an artery and a vein. The interior of the spermathecal sac was filled with a white mass friable, and when broken up of a "curdy " appearance. This when examined microscopically was seen to consist of a granular substance in which 1 could detect no structure and of multitudinous spermatophores (described below, p. 341). The immature Polytoreutus, to which I have referred, is probably not an example of P. hindei. But I a m unable to fix its specific identity further. I should have hardly thought it worth whileto give any account of this worm were it not for the fact that a study of it enables m e to point out that the female generative apparatus is not always developed before the male as I found to be the case in P. kilindinensis 1. In the present specimen the male pore was conspicuous and upon the middle of segment xvii. One of the ventral pair of seta? has disappeared-naturally the innermost one on either side. On the boundary-line between segments xviii. and xix. was the smaller aperture of the spermathecal sac. The ventral pair of seta? were not modified in the neighbourhood of this pore. Internally I could find no trace of the spermathecal sacs. On the other hand, the sperm-sacs were fairly developed and were divisible, as is often the case in this genus, into a thin proximal region and a stout distal region. They originated in segment xii., and the thin part of the sacs did not widen out until the fourteenth segment. At the distal end the two sacs were fused together as iu P. gregorianus 2. The terminal apparatus of the male ducts was only represented by a bursa with muscular walls, and of a long and thin form, not a spherical pouch as in Polgtoreutus generally. It suggested in fact the disconnected bursa of Stuhlmannia. If the shape was a transitory embryonic feature, it is of interest; but such a bursa may of course characterize the species. (2) On the Spermatophores of Polytoreutus. The spermatophores of this genus, the only genus of exotic earthworms save Alma :1 known to possess these structures, were discovered by myself in P. magilensis 4 and later in P. violaceus5. In the present species they appear to have a very different general appearance from those of the former species mentioned, but they 1 " A Contribution to our Knowledge of the Oligochreta of Tropical Eastern Africa," Quart. Journ. Micr. Sci. (n.s.) xxxvi. p. 240. 2 P. Z.S. 1901, vol. i. p. 193. 3 See Beddard, " O n the Clitellum and Spermatophores of an Annelid of the Genus Alma," P.Z. S. 1901, vol. i. p. 215. 1 " T w o new Genera and some new Species of Earthworms," Quart. Journ. Micr. Sci. (n.s.) xxxiv. p. 250. 5 "A Contribution to our Knowledge of the Oligochaeta of Tropical Eastern Africa," ib. xxxvi. p. 234. |