DARWIN AND WALLACE 39 
of the same process. Thus year by year the stock is 
improved. Any new feature that is favorable helps 
its possessor to survive, and, if happily mated, will 
show itself after a while in the entire group. This, 
in brief, is the underlying idea of Natural Selection, 
as Darwin conceived it. 
In 1842, at Lyell’s suggestion, Darwin wrote a 
short sketch of his ideas which he, two years later, 
expanded into a somewhat larger account. The manu- 
script of these early views of the theory was com- 
pletely lost and has only been recovered within the 
last few years. It was recently published under the 
editorship of Charles Darwin’s son, Francis. It is 
astonishing to see how clearly the first short sketch 
states the underlying conception which all of Dar- 
win’s subsequent work amplifies. Hooker was con- 
stantly urging Darwin to write out his whole theory 
in the form of a book, and Darwin had begun to do 
so in 1856. 
Meanwhile, down in the Moluccas, Alfred Russell 
Wallace had been lying sick of a fever contracted 
during his exploring expedition in that neighborhood. 
He had been studying the distribution of the animal 
life of the Malay Archipelago. Overcome by sick- 
ness, as he lay in bed, he began to think over a book 
which he had read not long before, “Malthus on 
Population,” Wallace had been pondering on the 
