epiblast
(ˈɛpɪblɑːst, -blæst)
[f. epi- + -blast.]
1. Bot. (See quot.)
| 1866 Treas. Bot., Epiblast, a small transverse plate (a second cotyledon), found on the embryo of some grasses. |
2. Biol. The outermost of the three layers constituting the wall of the blastoderm when fully formed.
| 1875 [see hypoblast 2]. 1877 Huxley Anat. Inv. An. i. 50 The inner wall of the sac is the hypoblast (endoderm of the adult), the outer the epiblast (ectoderm). 1881 Mivart Cat 319 The epiblast investing the whole ovum within the vitelline membrane. |
So epiˈblastic a.
| 1887 A. C. Haddon Introd. Study Embryol. ii. 36 The blastoderm of a newly-laid egg..consists of a definite epiblastic layer and an inferior irregular mass of rounded cells. 1893 A. M. Marshall Vert. Embryol. 371 The small epiblastic villi of the lower pole of the vesicle. 1921 A. Keith Hum. Embryol. (ed. 4) i. 12 An epiblastic or ectodermal set [of cells]. |