Abstract
[male][male] castrated at birth and receiving ovaries in the neck at this time or in the eye at puberty, showed [female] type of pituitary both in physiological response and in cell counts. [female][female] castrated at birth and receiving testis grafts at this time showed [male] type of pituitary after puberty. Genetical [female][female] castrated at birth or at puberty and grafted with ovaries produced the [female] cell pattern in the pituitary; castrated [male][male] receiving testis grafts produced the [male] pattern. If testis and ovary were present in one animal the tendency was to form the [male] pattern.