Abstract
Hypophyses transplanted under the kidney capsule rapidly lose their F.S.H.-content. This decrease is counteracted by the administration of testosterone (17[beta]-hydroxy-androst-4-en-3-one); an increase was even observed in the F. S. H.-content of the grafts. Treatment with progesterone (pregn-4-ene-3,20-dione) resulted in a non-significant increase in the F. S. H.-content of the grafts. Oestradiol was able to counteract to some extent the effect brought about by testosterone These results point to a direct action on pituitary F. S. H.-release-capacity, at least for testosterone.