Word Study
Gastrula
CIDE DICTIONARY
Gastrula, n. [NL., dim. fr. Gr. the stomach.].
An embryonic form having its origin in the invagination or pushing in of the wall of the planula or blastula (the blastosphere) on one side, thus giving rise to a double-walled sac, with one opening or mouth (the blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illust. under Invagination. In a more general sense, an ideal stage in embryonic development. See Gastræa. [1913 Webster]
OXFORD DICTIONARY
Gastrula, n. (pl. gastrulae) Zool. an embryonic stage developing from the blastula.
Etymology
mod.L f. Gk gaster gast(e)ros belly
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