part_of adult body adult female reproductive system adult ovary A band or u-shaped crescentic tube stretched horizontally across the posterior region of the body. The ovary is studded withinnumerable oocytes that expand in size during oogenesis, fill with brown yolk (vitellogenin) after mating and eventually migrate outinto the oviducts and vagina to exit the body. The ovary appears as a delicate, white tube in unfed females but becomes veryprominent during feeding, eventually appearing as one of the largest organs in the body. The ovary is similar in both ixodid andargasid ticks. In D. andersoni, the ovary is approximately 6 mm long by 64 - 110 microns in diameter. The tick ovary is of thepanoistic type, i.e., it lacks nurse cells. Fig. 16-1, Fig. 16-3, Fig. 16-4, Fig. 16-5, Fig. 16-6, Fig. 16-7, Fig. 16-8, Fig. 16-9, Fig. 16-10, Fig. 16-11, in Biology of Ticks ISBN:0-19-505910-7. TADS:0000400 TADS:0000400 default_namespace simple organ