Fig. 264.—Diagram of female genitalia. Ov., ovary (in part); Ovd., ovi­duct; Rec. sem., seminal re­cep­ta­cle; Ut., uterus (in part); Ovj., ovejector; Vag., vagina.

Fig. 264a.—Diagram of male genitalia of a strongylid. Test., testis (in part); S.V., seminal vesicle; c.g., cement gland surrounding ejaculatory duct; sp., spicules; cl., cloaca; gub., gubernaculum; p.p.a., pulvillus post-analis; g.c., genital cone; l.d., dorsal lateral line; l.v., ventral lateral line (the bursa is not shown).

Fig. 265.—Transverse section through the ovarian tube of Belascaris cati of the cat at various levels. To demonstrate the de­vel­op­ment (right to left) of the ova and of the rhachis. Mag­ni­fied.

At the blind end of the ovary there is a mass of protoplasm with numerous nuclei that multiply continuously. Gradually the nuclei arrange themselves in longitudinal rows (fig. 265) and the protoplasm commences to leave the periphery and surround each nucleus. The nearer to the uterus the more progressive is this loosening process, until club-shaped cells each containing a nucleus are developed. The most pointed end of each, however, is still attached to an axial fibre of protoplasm, the rhachis; probably this has some connection with the nutrition of the ova. Finally the ova fall off and reach the uterus, where they are fertilized and enclosed in shells.