Ovarian response of pinealectomized and intact white-footed mice kept under naturally short photoperiods.

Pinealectomized and intact adult female white-footed mice were maintained outdoors from 28 November to 2 January. At the termination of the experiment, ovarian weight was significantly greater (p less than 0.02) in the pinealectomized group compared with that of the intact animals. Microscopic examination of the ovaries revealed that those of the intact animals had fewer and smaller follicles than those from animals which had had their pineal glands removed.