What is "ectoblast"

Ectoblast \Ec"to*blast\, n. [Ecto- + Gr. ? bud, germ.] (Biol.)

1. The outer layer of the blastoderm; the epiblast; the ectoderm.

2. The outer envelope of a cell; the cell wall.
   --Agassiz. [1913 Webster] ||

n. (context dated biology English) the outer layer of the blastoderm; the ectoderm or epiblast

n. the outer germ layer that develops into skin and nervous tissue [syn: ectoderm, exoderm]