The Mechanism of Cell-Division

Abstract

1. Successive cleavages of the egg of Echinus miliaris are separated by equal intervals of time. 2. The time required for the complete cleavage cycle is independent of the size of the cell. 3. The rate of cell-division bears no obvious relationship to the rate of metabolism. 4. Cell-division and growth are the factors which determine the size of individual cells. In some cases these factors may establish a well-defined equilibrium, but in segmenting eggs they are probably quite independent of each other.