Child, Charles Manning (1869–1954)

US zoologist. He developed a theory of how the various cells and tissues in organisms are organized – by a gradation in the rate of physiological processes leading to relationships of dominance and subordination. Although not now thought to be correct, it was an important early contribution to the problem of functional organization within living organisms.

Child was born in Ypsilanti, Michigan, and studied zoology at the Wesleyan University in Connecticut and at Leipzig, Germany. He spent his academic career at the University of Chicago, becoming professor 1916.

In 1900, Child began a series of experiments on regeneration in coelenterates and flatworms. In 1910 he perceived that there is a gradation in the rate of physiological processes along the longitudinal axis of organisms. According to his gradient theory, developed 1911, each part of an organism dominates the region behind and is dominated by that in front. In general, the region of the highest rate of activity in eggs, embryos, and other reproductive parts becomes the head of the larval form; in plants it becomes the growing tip of the shoot or primary root. Regeneration follows the same principle.

In 1915 Child demonstrated that the parts of an organism that have the highest metabolic rates are most susceptible to poisonous substances, but also have the greatest powers of recovery after damage.