Abstract
A dose of procaine which was harmless to castrated mice produced a collapse of body tempera­ture when the animals were adrenalectomized. This effect of the alkaloid was inhibited by short-term treatment with desoxycorticosterone acetate or some related sex steroids, but not with thyroxin. Of the mice untreated with the steroids, a certain number survived adrenalectomy and the procaine test indefinitely. This percentage was significantly increased in the animals prepared with the protecting sex steroids, but was decreased to zero in the group treated with desoxycorticosterone acetate.