| 释义 |
‖ paraˈgastrula Embryol.
[f. para-1 1 + gastrula.]
A kind of gastrula occurring in some sponges, produced by invagination of the flagellate cells within the granular. Hence paraˈgastrular a., of or pertaining to a paragastrula; paragastruˈlation, the formation of a paragastrula.
1887Sollas in Encycl. Brit. XXII. 425/1 The two-layered sac thus produced is a paragastrula; its outer layer, known as the epiblast, gives rise to the ectoderm, the inner layer or hypoblast to the endoderm. 1890Cent. Dict., Paragastrular..Paragastrulation. |