Abstract

We wish here to consider the theory of a population or system made up of individuals whose number and size change with time. As usual, the description of these changes will be referred to as the kinetics, whereas the description of the special circumstances under which unchanging conditions subsist will be called the statics of the population. A third category, the conditions for a steady state, i.e., when the variables inside the system do not change, but linked variables outside do, will be described by what we shall call the rheostatics of the system. All three, statics, rheostatics, and kinetics are subdivisions of the general dynamics of the system.