Studies on the reproductive system of Philophthalmus gralli using techniques of transplantation and autoradiography.

Adult Philophthalmus gralli exposed in vitro to 3H-thymidine for 6 hr showed label on autoradiograms over actively dividing cells in the testes, ovary, and vitellaria. In worms transplanted to chicks, oogonia became primary oocytes within 4 days and these were first found enclosed in newly formed eggs by 12 days. Tertiary spermatogonia at the periphery of the testes developed into sperm by 144 hr and were found in the serminal vesicle by 168 hr. Vitelline cells required 96 hr to travel from gland areas to become incorporated into eggs. In adults labeled in vitro for 1 hr with 3H-tyrosine and transplanted singly to chicks, only 2 of 28 self-inseminated. Labeled worms transplanted with unlabeled worms never self-inseminated but cross-inseminated with approximately 40% of the available worms. Transplanted worms localized in the chick's orbit in 3 microhabitats. In only 1 of 21 experiments did a labeled worm inseminate unlabeled worms outside of the microhabitat where it was found.