So soon as the embryo begins to grow, the waste of cells begins; and continues until the death of the individual, however long he may live. “The knowledge is wanting,” says the Britannica, “which would tell us, when a certain limit has been attained, the process of income and expenditure balance and growth ceases.”—(Encyc. Brit. 17, p. 686.) “During life,” says Professor Martin, “all the formed elements of the body are constantly being broken down and removed; either molecularly, (that is bit by bit, while the general size and form of the cell or fibre remains unaltered) or in mass, as when the hairs and the cuticle are shed.” (Martin, Human Body, p. 670.)

See Encyc. Brit. 17, pp. 686-687; Martin, Human Body, pp. 451-476, 670-671; New International Encyc. 9, pp. 312-315.

The waste of cells affects the growth of the body, only so far as it tends to neutralize and offset the increase of the body by the multiplication of cells.