CELL, a term of various applications: (1) the compartments of a honey-comb, (2) one of the small structures compos ing the substance of plants, generally in distinguishable by the naked eye, and each, at least for a time, being a whole complete in itself, being composed of solid, soft, and fluid layers, different in their chemical nature, and disposed con centrically 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 corresponding to the different functions. By far the largest proportion of cells in the living succulent parts of plants are seen to be made up of three concentrical ly-disposed layers: first, an outer skin, firm and elastic, called the cell-wall or cell-membrane, consisting of a substance peculiar to itself. The second layer is soft and elastic, and always contains al buminous matter. And, thirdly, the cav ity inclosed by the protoplasm-sac is filled with a watery fluid called cell-sap.
(3) A term often applied to any small cavity, but properly restricted to a mi croscopical anatomical element with a nucleus cell-wall and cell-contents when typically formed. The animal cell is
ordinarily a closed sac, the environing membrane almost always consisting of a nitrogenous compound. The sac generally contains a liquid or semi-liquid proto plasm, in which are suspended molecules, granules, globules, or other very minute cells. Along with these are nuclei, which again contain nucleoli. Cells may be formed from a protoplasm existing with out the cell or within other cells. Or they may be made within others by what has hence been called an endogenous method 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.
(5) A structure in a wrought-iron beam or girder ; a tube consisting of four wrought-iron plates riveted to angle-iron at the corners.
(6) In electricity, a single jar, bath, or division of a compound containing a cou ple of plates, e. g., copper and zinc, united to their opposite or to each other usually by a wire.