Part 969

Hyp"o*gene (?), a. [Pref. hypo- + the root of Gr. &?; to be born: cf. F. hypogËne.] (Geol.) Formed or crystallized at depths beneath the earth's surface; -- said of granite, gneiss, and other rocks, whose crystallization is believed of have taken place beneath a great thickness of overlying rocks. Opposed to epigene.

Hyp`o*ge"ous (?), a. [See Hypogean.] (Bot.) Growing under ground; remaining under ground; ripening its fruit under ground. [Written also hypogÊous.]

||Hyp`o*ge"um (?), n.; pl. Hypogea (#). [L., fr. Gr. &?;, &?;, ||subterranean; &?; under + &?;, &?;, the earth.] (Anc. Arch.) The ||subterraneous portion of a building, as in amphitheaters, for the ||service of the games; also, subterranean galleries, as the catacombs.

Hyp`o*glos"sal (?), a. [Pref. hypo- + Gr. &?; the tongue.] (Anat.) Under the tongue; -- applied esp., in the higher vertebrates, to the twelfth or last pair of cranial nerves, which are distributed to the base of the tongue. -- n. One of the hypoglossal nerves.

Hy*pog"na*tous (?), a. [Pref. hypo- + Gr. &?; the jaw.] (Zoˆl.) Having the maxilla, or lower jaw, longer than the upper, as in the skimmer.

Hyp"o*gyn (?), n. (Bot.) An hypogynous plant.

Hy*pog"y*nous (?), a. [Pref. hypo- + Gr. &?; woman, female: cf. F. hypogyne.] (Bot.) Inserted below the pistil or pistils; -- said of sepals, petals, and stamens; having the sepals, petals, and stamens inserted below the pistil; -- said of a flower or a plant. Gray.

Hy`po*hy"al (?), a. [Pref. hypo- + Greek letter &?;.] (Anat.) Pertaining to one or more small elements in the hyoidean arch of fishes, between the caratohyal and urohyal. -- n. One of the hypohyal bones or cartilages.

Hy`po*nas"tic (?), a. [Pref. hypo- + Gr. &?; pressed close.] (Bot.) Exhibiting a downward convexity caused by unequal growth. Cf. Epinastic.

Hy`po*nas"ty (?), n. (Bot.) Downward convexity, or convexity of the inferior surface.

Hy`po*ni"trite (?), n. (Chem.) A salt of hyponitrous acid.

Hy`po*ni"trous (?), a. [Pref. hypo- + nitrous.] (Chem.) Containing or derived from nitrogen having a lower valence than in nitrous compounds.

Hyponitrous acid (Chem.), an unstable nitrogen acid, NOH, whose salts are produced by reduction of the nitrates, although the acid itself is not isolated in the free state except as a solution in water; -- called also nitrosylic acid.

||Hy`po*phar"ynx (?), n. [NL. See Hypo-, and Pharynx.] (Zoˆl.) An ||appendage or fold on the lower side of the pharynx, in certain ||insects.

Hy`po*phos"phate (?), n. (Chem.) A salt of hypophosphoric acid.

Hy`po*phos"phite (?), n. (Chem.) A salt of hypophosphorous acid.

Hy`po*phos*phor"ic (?), a. [Pref. hypo- + phosphoric.] (Chem.) Pertaining to, or derived from, or containing, phosphorus in a lower state of oxidation than in phosphoric compounds; as, hypophosphoric acid.

Hypophosphoric acid (Chem.), an acid, P2H4O6, produced by the slow oxidation of moist phosphorus, and isolated only as a solution in water. It is regarded as a condensation product of one molecule of phosphoric acid with one of phosphorous acid, by partial dehydration.

Hy`po*phos"phor*ous (?), a. [Pref. hypo- + phosphorous.] (Chem.) Pertaining to, or containing, phosphorus in a lower state of oxidation than in phosphoric compounds; as, hypophosphorous acid.

Hypophosphorous acid (Chem.) , an acid, H3PO2, whose salts are produced by the action of barium hygrate on phosphorus. It may be obtained from its water solution, by exaporation and freezing, as a white crystalline substance. It is a powerful reducing agent.

Hy*poph"yl*lous (?), a. [Pref. hypo- + Gr. &?; leaf.] (Bot.) Being or growing on the under side of a leaf, as the fruit dots of ferns.

Hy`po*phys"i*al (?), a. (Anat.) Of or pertaining to the hypophysis; pituitary.

||Hy*poph"y*sis (?), n. [NL., fr. Gr. &?; under + &?; nature, origin.] ||1. (Anat.) See Pituitary body, under Pituitary.

2. (Med.) Cataract.

Hy`po*plas"tron (?), n.; pl. Hypoplastra (#). [Pref. hypo- + plastron.] (Anat.) The third lateral plate in the plastron of turtles; -- called also hyposternum.

||Hy*pop"ti*lum (?), n.; pl. L. Hypoptila (#), E. Hypoptilums (#). ||[NL., fr. Gr. "ypo` beneath + &?; down.] (Zoˆl.) An accessory plume ||arising from the posterior side of the stem of the contour feathers ||of many birds; -- called also aftershaft. See Illust. of Feather.

||Hy`po*ra"di*us (?), n.; pl. Hyporadii (#). [Pref. hypo- + radius.] ||(Zoˆl.) One of the barbs of the hypoptilum, or aftershaft of a ||feather. See Feather.

||Hy`po*rha"chis (?), n.; pl. Hyporhachides (#). [NL., fr. Gr. "ypo` ||beneath + &?; spine.] (Zoˆl.) The stem of an aftershaft or ||hypoptilum. [Written also hyporachis.]