Word Study
allantois
CIDE DICTIONARY
allantois, n.
A membranous appendage of the embryos of mammals, birds, and reptiles, -- in mammals serving to connect the fetus with the parent; the urinary vesicle. [1913 Webster]
OXFORD DICTIONARY
allantois, n. (pl. allantoides) Zool. one of several membranes that develop in embryonic reptiles, birds, or mammals.
Derivative
allantoic adj.
Etymology
mod.L f. Gk allantoeides sausage-shaped
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