hypoblast
(ˈhɪpəʊ-, ˈhaɪpəʊblæst)
[f. hypo- 2 + -blast. Cf. F. hypoblaste.]
1. Bot. The flat dorsal cotyledon of a grass. ? Obs.
| [1830 Lindley Nat. Syst. Bot. 296 Esenbeck..seems to entertain the opinion that this cotyledon [of grasses] is a special organ, for which he retains Richard's name of hypoblastus. 1855 Mayne Expos. Lex., Hypoblastus.] 1882 in Ogilvie (ed. Annandale). 1886 in Syd. Soc. Lex. |
2. Biol. The inner layer of cells in the blastoderm.
| 1875 Huxley in Encycl. Brit. II. 51/1 In the embryo [of the Metazoa] the representatives of these two layers [ectoderm and endoderm] are the epiblast and hypoblast. 1877 ― Anat. Inv. Anim. i. 50 The inner wall of the sac is the hypoblast (endoderm of the adult), the outer the epiblast (ectoderm). 1897 Allbutt Syst. Med. I. 59 The endoderm or hypoblast, appears as a cul-de-sac. |
Hence hypoblastic (hɪpəʊ-, haɪpəʊˈblæstɪk) a., of or belonging to the hypoblast.
| 1877 Huxley Anat. Inv. Anim. xii. 663 The hypoblastic cells are invested by those of the epiblast. 1897 Allbutt Syst. Med. III. 680 The body cavity is the outgrowth from the primitive alimentary canal with the hypoblastic covering of which its lining membrane is continuous. |