In determining the parameters of structure and function in the group of patients designated as schizophrenic, increasing stress has been laid on endocrinal function. A great deal of work is being done to clarify adrenocortical function. We are about to begin similar studies in respect to thyroid responsivity, using radioactive iodine as an indicator. The present report deals with a third aspect of the endocrine system.The present study was undertaken to relate testicular changes such as those reported by Hemphill, Reiss and Taylor to adrenocortical and thyroid responsivity.