| 释义 |
parablast|ˈpærəblæst|
[f. para- + Gr. βλαστός sprout, germ: see -blast.]
†1. Path. (See quot.) Obs.
1857Mayne Expos. Lex., Parablasta..term used by Eisenmann for disease with anatomical conversion or alteration: a parablast.
2. Embryol. The nutritive yolk of a meroblastic ovum, as distinguished from the formative yolk or archiblast; also, a special layer of cells in the embryo, supposed by His to arise from the nutritive yolk, by others to belong to the mesoblast.
1876Klein in Q. Jrnl. Microsc. Sci. XVI. 116 This quasi⁓extraneous portion of the germ I will call parablast, in contradistinction to the segmented part or blastoderm of the authors, which I will term archiblast... However,..according to His, parablast is not a portion of the same substance of which the blastoderm consists, but is a part of the white yolk. 1884Science IV. 341/1 The parablast of Klein, the intermediate layer of American authors. 1888J. Beard in Q. Jrnl. Microsc. Sc. Oct. 195 There are here also plenty of mesoblast—pardon, ‘parablast’ cells in the neighbourhood.
Hence paraˈblastic a., pertaining or relating to the parablast (sense 2).
1885Landois & Stirling Text-bk. Hum. Physiol. II. 1128 The parablastic structure of blood and connective-tissue. 1888J. Beard in Q. Jrnl. Microsc. Sc. Oct. 195 When His regards the nuclei here present as mesoblastic or ‘parablastic’ cells, his view is just as much a gratuitous assumption as the whole parablastic doctrine. |