(rag) 
CHAPTER VII. 
THE THEORY OF SELECTION (DARWINISM). 
Darwinism (Theory of Selection) and Lamarckism (Theory of Descent).— 
The Process of Artificial Breeding.—Selection of the Different Indivi- 
duals for After-breeding.—The Active Causes of Transmutation.—Change 
connected with Food, and Transmission by Inheritance connected with 
Propagation.—Mechanical Nature of these Two Physiological Functions. 
—The Process of Natural Breeding: Selection in the Struggle for 
Existence.—Malthus’ Theory of Population.—The Proportion between 
the Numbers of Potential and Actual Individuals of every Species of 
Organisms.—General Struggle for Existence, or Competition to attain 
the Necessaries of Life.—Transforming Force of the Struggle for 
Existence.—Comparison of Natural and Artificial Breeding—Selection 
in the Life of Man.—Military and Medical Selection. 
It is, properly speaking, not quite correctly that the Theory 
of Development, with which we are occupied in these pages, 
is usually called Darwinism. For, as we have seen from 
the historical sketch in the previous chapters, the most 
important foundation of the Theory of Development—that 
is, the Doctrine of Filiation, or Descent—had already been 
distinctly enunciated at the beginning of our century, and 
had been definitely introduced into science by Lamarck. 
The portion of the Theory of Development which maintains 
the common descent of all species of animals and plants from 
the simplest common original forms might, therefore, in 
