The cyclical testicular events in the tropical weaver-finch Quelea quelea are basically the same as those of temperate zone species but are modified for a xerophilous mode of life. Photostimulation is not necessary for the development of the sexual cycle and immediately the abbreviated regeneration period is over Q. quelea will again achieve spermatogenesis under an unchanging 12 hr. 25 min. daylength. An abnormally long photoperiod of 17 hrs. influences gonad growth during the pre-nuptial acceleration phase and causes premature metamorphosis. It has no influence, however, on the duration of the regeneration phase. Some Q. quelea maintained in captivity develop a black plumage. This induced melanism is briefly reported.