In a previous communication from this laboratory, Deanesly and Rowlands [1936] analysed the growth of the reproductive and endocrine organs of male and female guinea-pigs. A similar investigation has now been made on the female rabbit, for which little information appears to be available. Brown, Pearce, and van Allen [1926a, b] analysed the organ-weights of apparently normal rabbits with reference to effects that might be produced by obscure lesions, but their data are not given in a form which enables any conclusions about the relation of organ- and body-weights to be drawn. Robb [1928, 1929] and Allanson [1932] investigated the growth of the pituitary body of male and female rabbits and agreed that its weight bears a constant relationship to that of the cleaned carcass. Material and Methods Animals. Eighty-three virgin female rabbits of from 280 to 2,640 g. gross body-weight were used. Forty-one were Dutch-marked, and forty-two were