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Show 816 MR. F. E. BEDDARD ON [Nov. 3, placed ; in A. ungulatus, where the generative organs are placed behind the clitellum, the latter is developed all round the body as in Perichata. Seta.-In A. nova zelandia and A. dissimilis the setse are disposed in four series of pairs, which is the typical arrangement of this genus ; in A. multiporus, as well as in Lankester's A. kerguele-nensis, the two setse of each pair become widely separated from each other, so that there are eight longitudinal and nearly equidistant rows of a single seta each. An intermediate condition is offered by A. schlegelii and A. capensis, where the setse are at first paired but subsequently come to lie further apart. I have not been able to detect any characteristic differences in the shape of the setse in the three species. In A. multiporus, and apparently in this species only, the setse are furnished with a pair of remarkable glands which do not seem to have been described in any other Earthworm. I have figured these in a paper upon the nephridia of this species, which will shortly be published in the ' Annales des Sciences Naturelles.' These glands are more or less pear-shaped, and terminate in a duct which approaches and possibly pours its secretion into the seta-sac; the relations of these glands to the seta reminded one very forcibly of the sebaceous glands of the hair-follicle to the hair. A considerable space is left in the longitudinal muscle-coat round each seta, which is partly occupied by a delicate network of connective tissue, and is traversed by the special muscles which serve to move the seta. In this network the glands referred to lie one rather in front of, and one rather behind the seta ; thev are composed of rounded cells each with a very distinct nucleus ; they are not concerned, or at least they are not directly concerned, in the production of new setse. The young seta? appear first in the substance of large peculiar cells placed below the setae, as has been described by Perrier and Vejdovsky, which have no relation whatever to these glands ; it is possible that they produce some poisonous secretion, which secures to the worm protection from its foes ; thev may correspond. The structure of the integument presents no special peculiarities : the epidermis consists of the ordinary columnar cells, among which are dispersed larger oval glandular cells ; these latter are absent round the various apertures (setse, nephridia, copulatory pouches, &c.) which pierce the integument. Between the epidermis-cells at their bases is a quantity of granular matter which has the appearance of pigment. The ultimate ramifications of the vascular system do not penetrate within the epidermic layer, except in the region of the clitellum ; and I mention this fact because in certain Earthworms the epidermis is vascular. In Megascolex1 and in Perionyx2 at any rate there are intra-epithelial capillaries. The study of species of Perionyx from Manilla, which I owe to the kindness of m y friend M r . H . E. Barwell, and which may or may not be identical with the species referred to above, enables m e to confirm this statement. 1 Trans. Roy. Soc. Edin. vol. xxx. pt. 2. 2 Proc. Roy. Phys. Soc. 1883-84, p. 89. |