246 



LAMARCK'S THEOEY OF THE 



[Ch. XXXIV. 



of common parents may deviate indefinitely from their original 



type. 



E'ow, if these doctrines be tenable, we are at once presented 

 with a principle of incessant change in the organic world ; 

 and no degree of dissimilarity in the plants and animals 

 which may formerly have existed, and are found fossil, would 

 entitle us to conclude that they may not have been the proto- 

 types and progenitors of the species now living. Accordingly 



MM. Lamarck and Geoffrey St. Hilaire declared their opinion 

 in the beginning of the present century that there had been 

 an uninterrupted succession in the animal kingdom, effected 

 by means of generation, from the earliest ages of the world 

 up to the present day, and that the ancient animals whose 

 remains have been preserved in the strata, however different, 

 may nevertheless have been the ancestors of those now in 

 being. In order to explain the facts and reasoning by which 

 this theory was originally supported, I cannot do better than 

 offer the reader a rapid sketch of the proofs which were 

 regarded by Lamarck as confirmatory of his views, shared 



as they were to a great extent by his contemporary, Geoffrey 

 St. Hilaire."^ 



Lamarc¥s arguments in favour 



the transmutation 



species. — The name of ^ species/ observes Lamarck, has been 

 usually applied to *^ every collection of similar individuals 

 produced by other individuals like themselves. 'f This defini- 

 tion, he admits, is correct; because every living individual 



* I have reprinted in this chapter, posed to the doctrine that the animals 



Avordfor word, my abstract of Lamarck's and pLints now living were the lineal 



doctrine of transmutation as drawn up descendants of distinct species only 



by me in 1832 in the first edition of the known to us in a fossil state. There is, 



* Principles of Geology,' vol. ii. chap. i. therefore, no room for suspicion that my 



I have thought it right to do this in jus- account of the Lamarckian hypothesis, 



tice to Lamarck, in order to show how written by me thirty-five years ago, de- 



nearly the opinions taught by him at rived any colouring from my own views 

 the commencement of this century re- 

 sembled those now in vogue amongst a 

 large body of naturalists respecting the 



Darwin, 

 indefinite variability of species, and the by which 



tending to bring it more into harmony 

 with the theory since promulgated by 



The law of natural selection, 



the last-mentioned great 



progressive development in past time of naturalist has thrown so much new light 

 the organic world. The reader must on the origin of species, will be ex- 

 bear in mind that when I made this plained in the next and succeeding 

 analysis^ of the ' Philosophic Zoolo- chapters. 

 gique/ in 1832, I was altogether op- f Phil. Zool. torn. i. p. 54. 1809. 



1 



/ 



1 



J 





C^' 



,.^>-j 



a 



V 



er^ 



n?* 



tea^.:. li ^^ 



tbi 



'-''>? ' 



tfbi 



pi ^Z ' for ^ 



if 



^'C to ^ 



to varv. 

 InorJer to 



ffor(i'\ 

 artrnmeut : 



different ». 



T 



crlobe, the mo 

 wkt onirlit to 



to limit and di 



lections are c 



a^J all our li 



arbitrary deU 

 iipon thp sH^f 

 form ^\^^Y -J 



%ly diii,r 

 ^ varieties. 



TllO r, 



%etli. 



re-ii 



1 



r, tlio 



natu 



**-i 





ai-e 



e 

 of 



t] 





