Gastraea

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Gastraea \Gas*tr[ae]"a\, n. [NL., from Gr. ?, ?, the stomach.]
     (Biol.)
     A primeval larval form; a double-walled sac from which,
     according to the hypothesis of Haeckel, man and all other
     animals, that in the first stages of their individual
     evolution pass through a two-layered structural stage, or


     gastrula form, must have descended. This idea constitutes the
     Gastr[ae]a theory of Haeckel. See {Gastrula}.
     [1913 Webster]