204 AS PARKES activities controlled by the adrenals must be clearly distinguished from dire& corticoid activity on the part of the gonad hormones. Similarly, changes produced by the adrenals in the gonads and thence in the accessory organs must be clearly distinguished from direct effects produced on the accessorv organs? either by the procluct, ion in the cortex of androgens, oestrogens or proiestogens. or by the gonad-hormone-like activity of the essential cortica’l hormones themselves.

In the review which follows, subdivision of subject is employed as far as possible to assist orderly presentation of the extremely heterogeneous mass of material. The subdivision cannot be complete, and some overlapping is unavoidable., Thus., discussion of tlhe effects of corticosterone on the reproductive organs and of the presence of gonadal hormones in the adrenals is difficult, to scparatle exactly from discussion of the effects on the reproductive organs of crude adrenal extracts, which may contain both of these substances. However, in t. he main, t! he a, im has been to make each section self-contained. The li terature discussed is that which appeared up to the end of 1941.