∞ generated and posted on 2016.08.31 ∞

Embryonic tissue that lines the gut.

Most animals consist of three primary germ layers which, going from outside in, are the ectoderm, the mesoderm, and the endoderm. In this case "in" is still on the "outside" of animal bodies, that is, lining either a cavity or tube that otherwise is directly connected to the world outside of the organismearly embryo these are the cells that line the archenteron in the gastrula, that is, of the primitive gut once the primitive gut has formed.

The endoderm is one of the two primary germ layers found in cnidarians, the other being ectodermal tissue.