Abstract
Assay was made of the gonadotrophic potency of the anterior pituitaries obtained from cocks, laying hens and non-laying hens in annual molting, of the Single Comb White Leghorns and partly those of the crossbreds. The degree of response was measured by the increment of the testicular weight of one-day-old cockerels.
Pituitaries from cocks were the richest in gonadotrophin content and pituitaries from non-laying hens showed a greater potency than those obtained from laying hens.
