Sex determination of the lesser bushbaby (Galago senegalensis).

The gross anatomy of the external genitalia of newborn to adult lesser Galago was described. The penis is perpendicular to the body wall at birth and by about 8 wk of age the testes have descended into the scrotum. In the adult male the testes are permanently descended, the scrotum sessile, the penis is oriented obliquely rostral, and the genitalia are covered by luxuriant pelage. In the young female, the clitoris is also perpendicular to the body wall and the labia and vaginal orifice, although not obvious, are located at its caudal base. In the adult female, the clitoris remains perpendicular, is slender, essentially devoid of fur, and has the urethral opening in its tip. The labia and vaginal orifice are at its caudal base, obscured by fur. Effective and reliable methods for differentiating males from females were outlined.