Cell

Collier's New Encyclopedia (1921)

a term of various applications: (2) one of the small structures composing the substance of plants, generally ineach, at least for a time, being a whole distinguishable by the naked eye, and complete in itself, being composed of solid, soft, and fluid layers, different in their chemical nature , and disposed concentrically from without inward. For the most part, a group of them is in close contact , and firmly united; they then form a cell-tissue. Each cell fulfills its own definite part in the economy of the plant, and shows a variety in form By far the largest proportion of cells in corresponding to the different functions. the living succulent parts of plants are seen to be made up of three concentrically-disposed layers : first, an outer skin, cell-membrane, consisting of a substance firm and elastic, called the cell-wall or peculiar to itself. The second layer is buminous matter. And, thirdly, the cavsoft and elastic, and always contains ality inclosed by the protoplasm-sac is filled with a watery fluid called cell-sap. cavity, but properly restricted to a mi- (3) A term often applied to any small croscopical anatomical element with a nucleus cell-wall and cell-contents when typically formed . The animal cell is ordinarily a closed sac, the environing nitrogenous compound. The sac generally membrane almost always consisting of a plasm, in which are suspended molecules, contains a liquid or semi-liquid protogranules, globules, or other very minute cells. Along with these are nuclei, which again contain nucleoli. Cells may be formed from a protoplasm existing without the cell or within other cells. Or they hence been called an endogenous method may be made within others by what has or by division or in other ways. (4) The space between the two ribs of a vault, or the space inclosed within the walls of an ancient temple. beam or girder; a tube consisting of four (5 ) A structure in a wrought-iron at the corners. wrought-iron plates riveted to angle-iron division of a compound containing a cou- (6 ) In electricity, a single jar, bath, or ple of plates, e. g., copper and zinc, united to their opposite or to each other usually by a wire. ian diplomat, born 1866.