10 IIISTOKICAL SKETCH. 



conclusion on the graJiuil cliangc of species by the dilTicully of distinguish- 

 ing species and varieties, bj- the almost perfect gradation of forms in certain 

 groups, and by the analogy of domestic productions. With respect to the 

 means of modification, he attributed something to the direct action of the 

 physical conditions of life, something to the crossing of already existing 

 forms, and much to use and disuse — that is, to the efTccts of habit. To this 

 latter agency he seems to attribute all the beautiful adaptations in Nature — 

 such as the long neck of the giraffe for browsing on the branches of trees. 

 But he likewise believed in a law of progressive development ; and, as all 

 the forms of life thus tend to progress, in order to account for the existence 

 at the present day of simple productions, he maintains that such forms arc 

 now spontaneously generated.* 



Geoffroy Saint-IIilaire, as is stated in his "Life," written by his son, sus- 

 pected, as early as IvOo, that what we call species are various degenerations 

 of the same type. It was not until 1828 that he puljjishcd his conviction 

 that the same forms have not been perpetuated since the origin of all things. 

 Geoffroy seems to have relied chiefly on the conditions of life, or the " monde 

 ambiant,''^ as the cause of change. lie was cautious in drawing conclusions, 

 and did not believe that existing species are now undergoing modification ; 

 and, as his son adds, " C'cst done un probleme h, reserver cntierement h 

 I'avenir, suppos6 meme que I'avenir doive avoir prise sur lui." 



In 1813 Dr. "W. C. AVells read before the Eoyal 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 im- 

 nniuity from certain tropical di.-cases, he observes, firstly, that all animals 



* I have taken the date of tlic first publication of Lamarck from Isid. Qeofl'roy 

 Saint-Ililaire'8 ("Hist. Nat. Guncralc," torn. 11., p. 405, 1S50) cxrcllent history of 

 opinion on this subject. In this work a full account is pivcn of Buftbn's conclusious 

 on the pame subject. It is curious how largely my grandfather, Dr. Erasmus Dar. 

 win, anticipated the views and erroneous grounds of opinion of Lamarck in Iiis 

 "Zoononiia" (vol. i., pp. 500-510), published in ITUt. According to Isid. Geoffroy, 

 there is no doubt that Goethe was an extreme partisan of similar views, ns shown 

 in llic introduction to a work written in 1794 and 1795, but not published <\\\ long 

 afterward: he has pointedly remarked ("Goethe als Naturforsclicr," von Dr. Karl 

 Meding, s. 31) tbat the future question for naturalists will be how, for Instance, cattle 

 got tlielr horns, and not for wbat they are used. It is rather a singular instance of 

 the manner in wliieh similar views arise at about the same time, that Goethe in Ger- 

 many, Dr. Darwin in England, and (icoffroy Saint-Ililai re (as we shall immediately 

 eee) in France, came to the same conclusion on the origin of species, in the years 

 1794-'95. 



