Their abdominal bones are like those of the marsupials; and they are furnished with pouches for their young, but have no teats, the milk being distilled into their pouches from the mammary glands.
During the early period of their sojourn in the pouch, the blind, naked, helpless young creatures (which in the great kangaroo scarcely exceed an inch in length) are attached by their mouths to the nipple of the mother, and are fed by milk injected into their stomach by the contraction of the muscle covering the mammary gland.
In the mammary gland during lactation or in sebaceous glands, caused by increased functional activity.
In a younger stage of their development, however, the young are carried in a temporary abdominal pouch, to which they are transferred after hatching, and into which open the mammary glands.
The secretion of milk, if occurring in the mammary gland, is much diminished or entirely arrested.
Examples of physiological hypertrophy are found in the ovaries, uterus and mammary glands, where there is an increased functional activity required at the period of gestation.
A X yew), the fluid secreted by the mammary glands of the division of vertebrate animals called Mammalia (see Mammary Gland), and primarily devised for the nourishment of their own young.