ziv HISTORICAL SKETCH. 



published his views in 1801 ; he much enlarged them in 1809 in 

 his 'Philosophic Zoologique,' and subsequently, in 1815, in the 

 Introduction to his ' Hist. Nat. des Animaux sans Yertebres.' In 

 these works he upholds the doctrine that species, including man, 

 are descended from other species. He first did the eminent service 

 of arousing attention to the probability of all change in the organic, 

 as well as in the inorganic world, being the result of law, and not 

 of miraculous interposition. Lamarck seems to have been chiefly 

 led to his conclusion on the gradual change of species, by the diffi- 

 culty of distinguishing species and varieties, by 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 condi- 

 tions of life, something to the crossing of already existing forms, 

 and much to use and disuse, that is, to the effects of habit. To 

 this latter agency he seems to attribute all the beautiful adapta- 

 tions 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 are now 

 spontaneously generated.* 



Geoffroy Saint-Hilaire, as is stated in his ' Life,' written by his 

 son, suspected, as early as 1795, that what we call species are various 

 degenerations of the same type. It was not until 1828 that he 

 published his conviction that the same forms have not been per- 

 ])tuated 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. He was cautious in drawing conclusions, and 

 did not believe that existing species are now undergoing modifica- 

 tion; and, as his son adds, "C'est done un probleme a reserve* 



* I have taken the date of the first publication of Lamarck from Isid. 

 Geoffroy Saint- Hilaire's ('Hist. Nat. Generale,' torn. ii. p. 405, 1859) 

 excellent history of opinion on this subject. In this work a full account is 

 given of Buffon s conclusions on the same subject. It is curious how largely 

 my grandfather, Dr. Erasmus Danvin, anticipated the views and erroneous 

 grounds of opinion of Lamarck in his ' Zoonomia ' (vol. i. pp. 500-510), pub- 

 lished in 1794. According to Isid. Geoffroy there is no doubt that Goethe was 

 an extreme partisan of similar views, as shown in the Introduction to a work 

 written in 1794 and 1795, but not published till long afterwards: he has 

 pointedly remarked (' Goethe als Naturforscher,' von Dr. Karl MedLig, s. 34) 

 that the future question for naturalists will be how, for instance, cattle got 

 their horns, and not for what they are used. It is rather a singular instance 

 of the manner in which similar views arise at about the same time, that Goethe 

 in Germany, Dr. Darwin in England, and Geoffrey Saint-Hilaire (as we shall 

 immediately see) in France, came to the same conclusion on the origin of 

 soecies, in the years 1 794-5. 



