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t necessarily parallel to the plane of deposition; -- usually produced by pressure. Basal cleavage, cleavage parallel to the base of a crystal, or to the plane of the lateral axes. -- Cell cleavage (Biol.), multiplication of cells by fission. See Segmentation. -- Cubuc cleavage, cleavage parallel to the faces of a cu…

Having a cleavage parallel with the base.

Cell division in which there is first a simple cleavage of the nucleus without change in its structure (such as the formation of chromosomes), followed by the division of the cytoplasm; direct cell division; -- opposed to mitosis. It is not the usual mode of division, and is believed by many to occur chiefly in highly…

the zeolites, usually occurring in square prisms or octahedrons with pearly luster on the cleavage surface. It is a hydrous silicate of calcium and potassium.

A lemon-yellow phosphate of uranium and calcium occurring in tabular crystals with basal cleavage, and in micalike scales. H., 2- 2.5. Sp. gr., 3.05-3.19.

Relating to, or forming, the base. Basal cleavage. See under Cleavage. -- Basal plane (Crystallog.), one parallel to the lateral or horizontal axis.

in rhombohedrons. It is somewhat harder than lead, and rather brittle; masses show broad cleavage surfaces when broken across. It melts at 507º Fahr., being easily fused in the flame of a candle. It is found in a native state, and as a constituent of some minerals. Specific gravity 9.8. Atomic weight 207.5. Symbol Bi.…

pertaining to or designating a hydroscopic monobasic acid, C10H15O5N3, obtained as a cleavage product from an acid of muscle tissue.

principally of silicate of iron, and crystallizing in hexagonal prisms with perfect basal cleavage; -- so named from the Swedish mineralogist Cronstedt.

Isometric or monometric; as, cubic cleavage. See Crystallization. Cubic equation, an equation in which the highest power of the unknown quantity is a cube. -- Cubic foot, a volume equivalent to a cubical solid which measures a foot in each of its dimensions. -- Cubic number, a number produced by multiplying a number…

planking, making angles of about 45º with the keel, in opposite directions. -- Diagonal cleavage. See under Cleavage. -- Diagonal molding (Arch.), a chevron or zigzag molding. -- Diagonal rib. (Arch.) See Cross-springer. -- Diagonal scale, a scale which consists of a set of parallel lines, with other lines crossin…

Having a single, distinct, diagonal cleavage; -- said of crystals. Mohs.

Applied to a form of egg cleavage seen in osseous fishes, which occurs only in a small disk that separates from the rest of the egg.

Pertaining to, or like, a dodecahedion; consisting of twelve equal sides. Dodecahedral cleavage. See under Cleavage.

ing the food yolk, at the commencement of segmentation, in a peripheral position, and the cleavage process confined to the center of the egg; as, ectolecithal ova.

e gem occurring in light green, transparent crystals, affording a brilliant clinodiagonal cleavage. It is a silicate of alumina and glucina.

t, cleft, or divided in the direction of the grain, like wood, or along natural planes of cleavage, like crystals. This crystal is a pellucid, fissile stone. Sir I. Newton.

ular) organisms by means of a process of self-division, consisting of gradual division or cleavage of the into two parts, each of which then becomes a separate and independent organisms; as when a cell in an animal or plant, or its germ, undergoes a spontaneous division, and the parts again subdivide. See Segmentation,…

red, etc., often very beautiful, crystallizing commonly in cubes with perfect octahedral cleavage; also massive. It is used as a flux. Some varieties are used for ornamental vessels. Also called fluor spar, or simply fluor.

ossessed by some crystalline rocks, of dividing into plates or slabs, which is due to the cleavage structure of one of the constituents, as mica or hornblende. It may sometimes include slaty structure or cleavage, though the latter is usually independent of any mineral constituent, and transverse to the bedding, it hav…