ALFRED RUSSEL WALLACE 529 



and this was enlarged during the sum- flashed upon me the idea of the sur- 

 mer of 1844 into one of 230 pages. — vival of the fittest — that the indlvid- 

 Darwin 's Autobiography, Chap. II. uals removed by these checks must be 



on the whole inferior to those that 

 survived. In the two hours that 

 elapsed before my ague fit was over, I 

 had thought out almost the whole of 

 the theory; and the same evening I 

 sketched the draft of my paper, and in 

 the two succeeding evenings wrote it 

 out in full, and sent it by the next post 

 to Mr. Darwin. — Wallace's "My Life," 

 p. 212. 



Danvin had been working upon the verification of the same idea for 

 twenty years. We owe to Sir Joseph Hooker and to Lyell the bringing 

 together of these independent but strikingly similar manuscripts. The 

 noble episode which followed of the joint publication of the discovery 

 "was prophetic of the continued care for truth and carelessness of self, of 

 the friendship, mutual admiration and cooperation between these two 

 high-minded men^ which affords a golden example for our own and 

 future ages. Each loved his own creations, yet undervalued his own 

 work; each accorded enthusiastic praise to the work of the other. 



It is a striking circumstance in the history of biology that Wallace's 

 rapidly produced sketch of 1858 " On the Tendencies of Varieties to 

 Part Indefinitely from the Original Type" not only pursues a line of 

 thought parallel to that of Darwin, except in excluding the analogy of 

 natural with human selection, but embodies the permanent substance of 

 the selection theory as it is to-day after fifty-four years of world-wide 

 research. It may be regarded as his masterpiece. The attempt has been 

 made by De Vries and others to show that Wallace in his " Darwinism " 

 of 1889 differed from Darwin on important points, but whatever may be 

 true of this final modification of the theory, a very careful comparison 

 of the Darwin- Wallace sketches of 1858 shows that they both involve the 

 principle of discontinuity ; in fact, fluctuation in the sense of plus and 

 minus variation was not recognized at the time ; the notion of variation 

 was that derived directly from field rather than from laboratory notes. 

 This is repeatedly implied in Wallace's language and especially in the 

 concluding sentence of his " Sketch " of 1858 : 



. . . that there is a general principle in nature which will cause many va- 

 rieties to survive the parent species, and to give rise to successive variations de- 

 parting further and further from the original type, and which also produces, in 

 domesticated animals, the tendency of varieties to return to the parent form. . . . 



Most or perhaps all the variations from the typical form of a species must 

 have some definite effect, however slight, on the habits or capacities of the in- 

 dividuals. Even a change of color might, by rendering them more or less distin- 

 guishable, affect their safety; a greater or less development of hair might modify 

 their habits. . . . The superior variety would then alone remain, and on a re- 



