Or Amnios, (from Amnion 460 a lamb, or lamb's skin). Martinus thinks it hath its name in allusion to , a vessel, used for the reception of blood insacrifice. It is also called armatura,aguina membrana, and pellicula, charta virginea, galea, indusium, amicu-lum. The internal membrane which surrounds the fŒtus. It is a fine, thin, transparent membrane, soft, but tough, smooth on its inside, but rough on the outer. Dr. Hunter says, that it runs over the internal surface of the placenta, and that this membrane, which seems not vascular in the human subject, makes the external covering of the navel string, to which it is most firmly united; and that viewed in a microscope, it appears to have blood vessels, but they are lymphatics. It is found in all animals, both viviparous and oviparous. The fluid contained in the amnios is of a dilute white colour, transparent by filtration, with a faint smell: it contains an albumen similar to that of the blood, muri-ated soda, and an uncombined alkali, with a small proportion of animal matter. In the liquor amnii of the cow there seems to be a peculiar acid, styled the amniotic acid. Annales de Chimie, xxiii. 269.