REPRODUCTION IN THE FEMALE HYRAX (DENDROHYRAX ARBOREA RUWENZORII)

摘要: An investigation carried out on 58 female hyraxes from a collection (sex ratio 57·04±4·26 per cent) made in the Ruwenzori region of Uganda. The juvenile ovary is bean-shaped and exhibits no sub-surface crypts; mature deeply lobed. Ovaries all animals contain prominent interstitial tissue very many follicles at stages development up to antrum formation. There high incidence follicular atresia. appears when follicle 0·47 mm diameter, size immediately prior rupture 1·7 mm. From initiation formation, theca interna normal hypertrophied. The fully formed corpus luteum averages 1·6 but if pregnancy follows, it grows 2·1 It maintains this an appearance activity throughout pregnancy. All corpora lutea are by ovulation, average number being 1·49. accessory lutea, luteal derived exclusively thecae internae ruptured follicles. Old readily identifiable histologically probably persist life. One or two young born time, parturition followed lactation anoestrus which terminated infertile ovulation. The left ovulates more frequently than right, there evidence intrauterine migration ova. Prenatal mortality, calculated fifteen 9·5 cent. some strains potentially higher lower fecundity population. There be definite breeding season, births mid-year other times. The structure bicornuate uterus described, significance mode formation discussed.