Darwin-Wallace Celebration. 37 



embodied the fundamental principle of the "Struggle for 

 Existence," which everywhere stares us in the face. There 

 Malthus stopped : it required " the flash of inspiration," 

 which has been spoken of to-day, to see that the necessary 

 consequence was the " Survival of the fittest." 



The thought of each age is the foundation of that which 

 follows. Darwin was an admirer of Paley, a member of his 

 own College. He swept in the whole of Paley's teleology, 

 simply dispensing with its supernatural explanation. John 

 Ray, another distinguished son of Cambridge, and perhaps 

 the greatest naturalist of his time, took the first step towards 

 a natural classification of plants. We now know that what 

 he and those who followed him were unconsciously striving 

 after was the principle of descent which Darwin established. 



Fifty years ago, Darwin and Wallace revealed two things 

 to us. They gave the world a rational explanation of the 

 evolution of living forms by descent. Of this it had long been 

 expectant but could not find the " how." Natural selection 

 was " the new creative thought." We now recognise it as an 

 influence, inevitable and inexorable, which pervades us like 

 gravitation. As Professor Karl Pearson has said, it is 

 " something we run up against at once, almost as soon as we 

 examine a mortality table." For the analysis of such a table 

 shows " a selective death-rate." It is the continuous adjust- 

 ment of the organism to its surroundings, in the widest 

 meaning of the words, as a condition of its existence. Its 

 operation makes for complexity, for it is irreversible and 

 builds on what has preceded. Yet it is not identical 

 with progress, for, as Huxley pointed out, that " which 

 survives in the struggle for existence may be, and often is, 

 the ethically worst." But whether it makes for perfection 

 or degeneration, natural selection, slowly and unobserved, is 

 incessantly at work moulding the face of organic nature. 



