Charles Robert Darwin. 31 



the most notable of nineteenth century books, an epoch- 

 making book if ever there was one. The amenities of 

 scientific literature have not a brighter page to show than 

 those recording the mutual relations of Darwin andWallace as 

 simultaneous promulgators of the grandest generalization 

 of the modern world. Darwin was ever quick and gen- 

 erous in his assertion of the independent origin of Mr. Wal- 

 lace's conclusions, and Mr. Wallace was never backward in 

 declaring not only the priority of Darwin's view, but the 

 less comprehensive and conclusive character of his own in- 

 vestigations. 



" The Origin of Species " was not intended as an exhaust- 

 ive statement of the argument for natural selection, but 

 only as an outline of this argument. But it was an outline 

 in some five hundred closely printed pages, an outline that 

 a less exigent spirit would have thought sufficiently exhaust- 

 ive. It was the hope of Darwin to fill out this outline of 

 his theory in all its parts. What the extent of the work 

 would have been if he had done so can be inferred from the 

 extent of "Animals and Plants under Domestication," pub- 

 lished in 1868. Here, in two volumes, we have a thousand 

 pages which are only an expansion of the first chapter in 

 the " Origin of Species." There is every reason to believe 

 that Darwin had at his command a range of observation 

 and experiment that would have enabled him to expand 

 every chapter in the " Origin of Species " to a like degree. 

 But for such expansion there seemed to be no crying need. 

 Other men were entering into his labors and carrying them 

 on with great enthusiasm and success. Nevertheless, all 

 that he wrote, with hardly an exception, after the " Origin 

 of Species" was to confirm and illustrate the doctrine of 

 that marvelous book. Indeed, he found it quite impossible 

 to study any aspect of nature that did not fall into line 

 with his supreme idea. The nature of his studies may be 

 gathered from the titles of his successive works : — " Fertil- 

 ization of Orchids," " Cross and Self Fertilization of Plants," 

 "Forms of Flowers," "Movements and Habits of Climb- 

 ing Plants," "Insectivorous Plants," "Movements of 

 Plants," "The Descent of Man and Sexual Selection," — the 

 second part of which was an expansion into five hundred 

 pages of a few paragraphs in the " Origin of Species," — 

 and the book on " Earthworms " and " Artificial Selection 

 under Domestication" of which I have already spoken. 



