The upper region of an ovum or blastula, which is free of yolk or occupied by small, rapidly dividing cells with little yolk; contrasted with vegetal hemisphere.
Origin
Late 19th century; earliest use found in Haeckel's Evolution of Man.
Definition of animal hemisphere in US English:
animal hemisphere
noun
Embryology
The upper region of an ovum or blastula, which is free of yolk or occupied by small, rapidly dividing cells with little yolk; contrasted with vegetal hemisphere.
Origin
Late 19th century; earliest use found in Haeckel's Evolution of Man.