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cleoplasm; -- esp. applied to a body formed in the developing ovum from the plasma of the nucleus of the germinal vesicle.

The rudiment of a seed. It grows from a placenta, and consists of a soft nucleus within two delicate coatings. The attached base of the ovule is the hilum, the coatings are united with the nucleus at the chalaza, and their minute orifice is the foramen.

. (b) Specifically: (Organ. Chem.) That two groups or radicals substituted in the benzene nucleus are opposite, or in the respective positions 1 and 4; 2 and 5; or 3 and 6, as paraxylene; paroxybenzoic acid. Cf. Ortho-, and Meta-. Also used adjectively.

ty. Channing. Parent cell. (Biol.) See Mother cell, under Mother, also Cytula. -- Parent nucleus (Biol.), a nucleus which, in cell division, divides, and gives rise to two or more daughter nuclei. See Karyokinesis, and Cell division, under Division.

A hypothetical hydrocarbon, C5H10, metameric with the amylenes, and the nucleus of a large number of derivatives; -- so named because regarded as composed of five methylene residues. Cf. Trimethylene, and Tetramethylene.

The protoplasmic matter which surrounds the entoblast, or cell nucleus, and undergoes segmentation. -- Per`i*blas"tic, a.

Of or pertaining to a nucleus; situated around a nucleus; as, the perinuclear protoplasm.

The hypothetical radical PH4, analogous to ammonium, and regarded as the nucleus of certain derivatives of phosphine.

The radical PO, regarded as the typical nucleus of certain compounds.

d with nuclein in cell nuclei, and by some considered as the fundamental substance of the nucleus.

ition of certain alkaloids, as a colorless liquid with a peculiar pungent odor. It is the nucleus of a large number of organic substances, among which several vegetable alkaloids, as nicotine and certain of the ptomaïnes, may be mentioned. See Lutidine.

hetically as a colorless liquid, C4H5N, having on odor like that of chloroform. It is the nucleus and origin of a large number of derivatives. So called because it colors a splinter of wood moistened with hydrochloric acid a deep red.

a pungent colorless liquid by the distillation of alkaloids, bones, coal tar, etc. It the nucleus of many organic bodies, especially of certain alkaloids and related substances; hence, by extension, any one of the series of alkaloidal bases of which quinoline proper is the type. [Written also chinoline.]…

d lies between the entoblast and ectoblast. See Illust. of Invagination. -- Segmentation nucleus (Biol.), the body formed by fusion of the male and female pronucleus in an impregnated ovum. See the Note under Pronucleus. -- Segmentation of the ovum, or Egg cleavage (Biol.), the process by which the embryos of all the…

The nucleus of the sperm cell.

A hypothetical radical, SH3, regarded as the type and nucleus of the sulphines.

h.) Same as Tailpiece. -- Tail of a comet (Astron.), a luminous train extending from the nucleus or body, often to a great distance, and usually in a direction opposite to the sun. -- Tail of a gale (Naut.), the latter part of it, when the wind has greatly abated. Totten. -- Tail of a lock (on a canal), the lower en…

A cellular layer derived from the nucleus of an ovule and surrounding the embryo sac. Cf. Quintine.

A double benzene and thiophene nucleus, C8H6S, analogous to naphthalene, and like it the base of a large series of derivatives. [Written also thionaphtene.]

A double thiophene nucleus, C6H4S2, analogous to thionaphthene, and the base of a large series of compounds. [Written also thiophtene.]