J. Morris Slemons,
The Prospective Mother, a Handbook for Women During Pregnancy
“ THE PLACENTAL STAGE.—Although the third stage is chiefly concerned with the separation and the delivery of the after-birth, on which account it is known as the placental period, the description of other no less remarkable events belongs here. Even after the infant is born the umbilical cord extends from its navel to the placenta, just as it has done throughout pregnancy. Among larger mammals separation of the new-born from the mother is brought about in one of two ways; sometimes the activity of the young breaks the navel-string, though more frequently the mother bites it in two. ”
