HISTORICAL SKETCH 443 



biant" as the cause of change. He was cautious in drawing con- 

 clusions, and did not believe that existing species are now under- 

 going modification; and, as his son adds, "C'est done un prob- 

 leme a reserver entierement a I'avenir, suppose meme que I'avenir 

 doive avoir prise sur lui." 



In 1813 Dr. W. C. Wells read before the Royal Society "An 

 Account of a White Female, part of whose skin resembles that of 

 a Negro;" but his paper was not published until his famous "Two 

 Essays upon Dew and Single Vision" appeared in 1818. In this 

 paper he distinctly recognizes the principle of natural selection, 

 and this is the first recognition which has been indicated; but he 

 applies it only to the races of man, and to certain characters alone. 

 After remarking that negroes and mulattoes enjoy an immunity 

 from certain tropical diseases, he observes, firstly, that all animals 

 tend to vary in some degree, and, secondly, that agriculturists 

 improve their domesticated animals by selection; and then, he 

 adds, but what is done in this latter case "by art, seems to be done 

 with equal efficacy, though more slowly, by nature, in the forma- 

 tion of varieties of mankind, fitted for the country which they 

 inhabit. Of the accidental varieties of man, which would occur 

 among the first few and scattered inhabitants of the middle re- 

 gions of Africa, some one would be better fitted than others to 

 bear the diseases of the country. This race wculd consequently 

 multiply, while the others would decrease; not only from their 

 inability to sustain the attacks of disease, but from their incapacity 

 of contending with their more vigorous neighbors. The color of 

 this vigorous race I take for granted, from what has been already 

 said, would be dark. But the same disposition to form varieties 

 still existing, a darker and a darker race would in the course of 

 time occur, and as the darkest would be the best fitted for the 

 climate, this would at length become the most prevalent, if not 

 the only race, in the particular country in which it had originated." 

 He then extends these same views to the white inhabitants of 

 colder climates. I am indebted to Mr. Rowley, of the United States, 

 for having called my attention, through Mr. Brace, to the above 

 passage of Dr. Wells's work. 



The Hon. and Rev. W. Herbert, afterward Dean of Manchester, 

 in the fourth volume of the "Horticultural Transactions," 1822, 

 and in his work on the "Amaryllidaceae" (1837, pp. 19, 339), de- 

 clares that "horticultural experiments have established, beyond 

 the possibility of refutation, that botanical species are only a 

 higher and more permanent class of varieties." He extends the 

 same view to animals. The dean believes that single species of 



