What is "placentation"

Placentation \Plac`en*ta"tion\, n.

1. (Anat.) The mode of formation of the placenta in different animals; as, the placentation of mammals.

2. (Bot.) The mode in which the placenta is arranged or composed; as, axile placentation; parietal placentation.

n. (context biology English) the local fusion of the embryonic stage of an animal to its parent for physiological exchange to promote the growth and development of the young; involves a placenta in non-egglaying mammals

1. n. the formation of the placenta in the uterus

2. arrangement of the ovules in the placenta and of the placentas in the ovary

In biology, placentation refers to the formation, type and structure, or arrangement of placentas. The function of placentation is to transfer nutrients from maternal tissue to a growing embryo. Placentation is best known in pregnant female mammals ( eutheria), but also occurs in other animals, eggs ( yolk sac placentation) and flowering plants.