Mechanism and Significance of the ‘Refractory Period’ in the Avian Testis Cycle

Abstract

BURGER¹ asserts that the “problem of refractoriness is perhaps the greatest relatively unsolved problem in reproduction”. This problem, except in its ultimate details, may, in fact, have been solved². It can be said that the “refractory period” (of Bissonnette³) or “dead sexual season” (of Polikarpova⁴) in seasonal birds is that part of the testis cycle during which the tubules are in a state of post-spermatogenetic lipoidal metamorphosis, and before the newly regenerated Leydig cells of the interstitium have become sufficiently mature and lipoidal to respond to neurohumoral influences initiated by factors in the environment.