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Show 1901.] AND ARRANGEMENT OF EARTHWORMS. 193 contracted state of the worm render it a little difficult to m ap this portion of the sperm-sacs accurately. The reason is that the greatly bulged divisions of the sperm-sacs do not lie so plainly and simply side by side as they do both anteriorly and posteriorly; they are somewhat intertwined by the exigencies of space in relation to their o w n increasing bulk, but do not, at least so far as I have been able to ascertain, intercommunicate at these points. In any case there is no doubt that at the very end of their course the two sperm-sacs are perfectly continuous, there being no externally visible break where one passes into the other ; the two sacs thus end posteriorly in a somewhat horseshoe-shaped loop. The spermiducal glands measure about 20 m m . in length • but they do not occupy a corresponding length of the body since'each is bent once and sharply upon itself; this bend does not mark off the spermiducal gland into two regions, though each gland can be so divided. W h e n the gland emerges from the terminal bursa Text-fig. 53 Polytoreutus gregorianus. Genitalia, x 2. A, posterior lateral diverticula of spermathecal sac; F, anterior do.; E, recep-taculum ovorum; D, median part of spermathecal sac; C, terminal bursa copulatrix, into which open B spermiducal glands. copulatrix, through which it communicates with the exterior, it is at first narrow ; it then gradually widens and forms an elongated heart-shaped tube, from tbe middle of the end of which arises the distal part of the spermiducal gland; the relations of the latter to the former part are very much those of a small intestine opening into a large intestine which is furnished at the junction of the two with two short blunt caeca. The point of junction of the two |