342 PRINCIPLES OF ANIMAL BIOLOGY 



All this time Darwin had published nothing of his discoveries. He 

 wanted to be very sure of his ground. He had confided his ideas to only 

 a few friends, among them the botanist Joseph Hooker and the geologist 

 Sir Charles Lyell. It is doubtful whether he would have published as 

 early as he did but for a curious coincidence. In 1858, Alfred Russel 

 Wallace, an able young naturalist then in the orient, sent to Darwin a 

 sketch of a theory of which he desired Darwin's opinion. To the latter's 

 surprise, this theory proved to be no other than the theory of natural 

 selection, or survival of the fittest; and as Wallace afterwards related, 

 he had first got the idea from reading the work of Malthus, "Essay on 

 Population." At first Darwin was inclined to withhold his own manu- 

 script, and allow that of Wallace to be published. But since Wallace's 

 idea was admittedly a sudden one, in favor of which he had collected no 

 facts whatever, whereas Darwin had long been gathering data relative 

 to it, Darwin's friends protested. It was finally arranged to present 

 extracts from both Darwin's and Wallace's manuscripts simultaneously 

 to the Linnsean Society of London, which was done in 1858. History 

 has adjudged practically the entire credit for the theory of natural selec- 

 tion to Darwin; but it is to the immortal honor of both of its authors 

 that neither allowed a dispute regarding priority to mar the launching 

 of their epoch-making hypothesis. 



Darwin's theory was developed at length in ''The Origin of Species," 

 published in 1859. At intervals after that date he published books on 

 specific phases of the evolution problem. New hypotheses were from 

 time to time advanced, which were intended to supplement the theory of 

 natural selection, such as sexual selection, pangenesis, and others. Of 

 Darwin's writings subsequent to 1859, his "Animals and Plants under 

 Domestication " is at once the most readable and most important. Prac- 

 tically all of these books are so written as to be intelligible to persons 

 without biological training. To this circumstance, more than to any 

 other, perhaps, is due the rapid acceptance of the evolution doctrine. 

 It is true, the time was ripe for such an advance; and then there was Hux- 

 ley (Fig. 235), who championed Darwin's views in popular lectures. But 

 it is doubtful whether evolution would have occupied the attention of the 

 laity, had it not been for the non-technical presentation of it which Dar- 

 win himself gave in his books. 



Evolution was not accepted without opposition. The churchmen 

 were reluctant to regard the story of the creation in any other than a 

 strictly literal way. In the main, however, they watched the progress 

 of the new doctrine with good nature, and at present the leading clergy 

 of most churches are as firmly convinced of evolution as are the biologists. 

 Oc(!asionally even now there is a cry that evolution is being abandoned 

 by scientific men, but the arguments in support of such a statement are 

 usually found to confuse the fact of evolution with the cause or method of 



