“…and Hainan(449) have described the development of the mammary glands of the dog during pseudo-pregnancy;in this animal the constructive phase proceeds so far that the breakdown process at the end of pseudo-pregnancy actually leads to lactation.In Dasyurus the development of the mammary glands during pseudo-pregnancy is indistinguishable from that which occurs during true pregnancy; as in other species the growth of the gland is correlated with that of the corpus luteum. In the guinea-pig, according to Loeb and Hesselberg (402), the mammary tissue undergoes very little development during the luteal phase of the ordinary dioestrous cycle in the unmated animal, but there is appreciable growth when the corpora lutea are caused to become abnormally persistent by hysterectomy.During the dioestrous cycle, even when there is a definite luteal phase, as in the guinea-pig, the development of the gland is not normally carried far enough to result in the actual secretion of milk.Woodman and Hammond(644), however, report that virgin heifers after a series of dioestrous cycles may occasionally secrete a small quantity of milk.Dieckmann(159) has described the growth which takes place in the mammary gland during the luteal phase of the human menstrual cycle. None of the changes characteristic of the luteal phase are found after ovariectomy or removal of the corpora lutea.The control of this mammary development during pseudo-pregnancy is known definitely to be endocrine in nature.…”