CELL

is the term used to denote the elements of which the body is built. All living matter is composed of cells; in the lowest forms of plant and animal life, the organism consists of one cell only, in the ge forms of more than one cell, except at the Poginnlig of life. The beginning of each individual is an ovum or egg, which is a single cell; but directly the egg begins to devel =o the one cell becomes two, and the two four, and so on, until a maas of cells results which differentiate into the various organs of the future animal. In certain cases the cells secrete material in which they lie imbedded; for instance in bone, which consists of few cells and much intercellular. chalky material. In other cases the cells remain in contact with one another with a minimum of intercellular material; in fact, only just enough to cement the cells firmly ey ek skin is aa example of this form. In yet a third a& @: [s. 341]