英语释义
1
n. A primeval larval form; a double-walled sac from which,
2
according to the hypothesis of Haeckel, man and all other animals, that
3
in the first stages of their individual evolution pass through a
4
two-layered structural stage, or gastrula form, must have descended.
5
This idea constitutes the Gastraea theory of Haeckel. See Gastrula.