Abstract
Hypophysectomy induces an anemia in the rat, while bleeding the hypophysectomized rat causes a superimposed hemorrhagic anemia. Intact normal and sham-operated adult female rats of the Wistar strain, bled 2% of body weight, recover completely from the hemorrhagic anemia within 10 days. Hypophysectomized rats bled at various intervals after the operation exhibit partial regeneration of blood elements on the 10th day after bleeding. Maximal recovery is reached at this time with no further regeneration occurring subsequently. Therefore, the presence of the hypophysis is necessary for complete regeneration of blood after hemorrhage.