Abstract
Thiouracil injns. into baby rats resulted in retardation of tooth eruption and opening of the eyelids. Desoxycorticosterone, when injected into thiouracil treated rats, antagonized these developmental effects so that the time of tooth eruption and eyelid opening returned to normal. It had no antagonizing effect, however, on the stunting of body growth or on the histologic picture of the thyroid gland produced by thiouracil.