Allantois

Allantois, a membrane enveloping the foetus in mammals, birds, and reptiles.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Allan, Sir William * Allard`
Alkalies
Alkaline earths
Alkaloids
Alkmaar`
Alkmer, Henrik van
All the Talents, Administration of
Al`lah
Allahabad`
Allan, David
Allan, Sir William
Allantois
Allard`
Allegha`ny
Allegha`ny Mountains
Allegorical interpretation
Allegory
Allegri
Al`leine, Joseph
Allen, Bog of
Allen, Ethan
Allen, Grant