436 The Ohio Naturalist. [Vol. VI, No. 3, 



with a central opening in the sixth segment; pairs of sperma- 

 tothecae in the third, fourth, and fifth segments; and a clitellum 

 confined to the ventral surface of the fifth, sixth and seventh 

 segments. 



Among a number of individuals of an undescribed species of 

 Aelosoma, taken from the vivarium of the University of Penn- 

 sylvania about December 1st, 1901, ten were found containing 

 the sex products in various stages of development. Of these 

 three were hermaphroditic, four contained ova alone, and three 

 male sex cells alone. Thus while this species is plainly her- 

 maphroditic, it seems probable that eggs and sperms do not 

 mature simultaneously in the same individual. The occurrence 

 of ripe spermatozoa, (represented in Fig. 5), and immature ova 

 in the same individual indicates that the species is protandrous, 

 but the evidence is insufficient to decide this question. Many 

 of those in which sex cells were found were also reproducing 

 asexually in the usual manner. 



The ova, (Fig. 1), are found in the fifth, sixth, and seventh 

 segments, in some cases in only one of these segments, in others 

 in all three. One individual, however, contained ova in the 

 fourth, fifth and sixth segments. They are attached to the thin 

 peritoneal layer lining the body cavity, and lie below the stom- 

 ach and lateral to the ventral blood vessel, In Fig. 1 the larger 

 of the two ova represented is by far the largest observed, measur- 

 ing ca. 55 micra across, and is probably approaching maturity. 

 It occupies a median position, compressed between the stomach 

 wall (st.) and the ventral hypodermis (hyp.), the walls of the 

 ventral blood vessel (b. v.) having been ruptured. The smaller 

 ovum occupies the usual position. Both ova possess a vesicular 

 nucleus (germinal vesicle) containing scattered chromatin 

 granules and a large nucelolus, enclosing a vacuole. The cyto- 

 plasm is packed with deeply staining yolk granules. The num- 

 ber of ova is small in all of my preparations, one of the best 

 showing only eight in the three ova-bearing segments. No 

 evidences were found of an oviduct, a clitellum, or of sperm- 

 atothecae. 



Although no clear evidence of the presence of testes was found 

 the ripening male sexual elements (Figs. 2-5) were seen floating 

 free in the body cavity, being found in greatest abundance near 

 the point where stomach and intestine join. They appear as 

 groups or nests of cells, more or less spherical in form. Four 

 kinds of these can be readily distinguished by the character of 

 their component cells; the primary spermatocytes, the secondary 

 spermatocytes, the spermatids, and the spermatozoa. The 

 primary spermatocytes, (Fig. 2), form cell nests made uji of 

 comparatively few cells, in size the largest of the series, their 

 nuclei measuring ca. 3.9 micra in diameter. As Fig. 2 shows, 



