protogeneticadj.
/ˌprəʊtə(ʊ)dʒᵻˈnɛtɪk/, U.S. /ˈˌproʊdoʊdʒəˈnɛdɪk/ 1. Botany. Designating intercellular spaces which are formed in the early stages of growth of a plant; = protogenic adj.1 3. rare.
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1884 F. O. Bower & D. H. Scott tr. H. A. de Bary Compar. Anat. Phanerogams & Ferns 200 The stomata of the epidermis..are a special case of schizogenetic and protogenetic [Ger. schizogener und protogener] spaces, which usually contain air.
1984 J. E. Mickle Taxon. Specimens Pennsylvanian Age Marattialean Fern 27/1 A possible interpretation is that some lacunae form near the apex in a protogenetic lysigenous fashion.
2. Geology. Designating mineral inclusions in which the included crystals are older than the host material.
ΚΠ
1974 E. J. Gübelin Internal World Gemstones 42/2 Inclusions which originated before the formation of the host crystal surrounding them are termed ‘protogenetic’. They were adopted, ready-made, into its interior.
1991 C. S. Hurlbut & R. C. Kammerling Gemology (ed. 2) viii. 123/1 Protogenetic inclusions cannot always be recognized as such, for the same mineral pair (inclusion and host) may result from another process.
1999 Science 6 Aug. 859/2 Useful criteria to distinguish between and among protogenetic (prediamond), syngenetic (simultaneous formation with diamond), and epigenetic (later than diamond) mineral inclusions in diamond.
This entry has been updated (OED Third Edition, September 2007; most recently modified version published online March 2022).
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adj.1884