Testosterone propionate is less effective in stimulating the seminal vesicles of rats deficient in pteroyl-glutamic acid than those of normal rats. The reduced responsiveness to the hormone seen in the pteroylglutamic-acid-deficient rats is, however, explained by the concomitant inanition rather than by the vitamin deficiency of itself. The action of testos-terone propionate on immature rat seminal vesicle wt., there-fore, is not dependent upon pteroylglutamic acid.