116 SPECIES. 



partial chronological statement concerning the grave question 

 of species.* " Circumstances have an influence upon form 

 and organisation/' such is the fundamental principle of La- 

 marck's doctrine ;f he says the same elsewhere :J "Circum- 

 stances determine positively what each body may be ;" and he 

 concludes, " among living bodies, nature only shows indivi- 

 duals who succeed one another. Species, amongst themselves, 

 are only relative, and are only temporarily so." 



If from these general considerations we enter in detail into 

 Lamarck's theory, we find room for the objections with which 

 the opponents of the system of variety are engrossed, with 

 which they have made those weapons of ridicule which act so 

 well on minds which are not forewarned, and who are ignorant of 

 this master's whole system of ideas. The grandeur of Lamarck's 

 views, the majestic simplicity of his theory, ought to be suffi- 

 cient to shield him from such attacks. He saw at the begin- 

 ning organic matter grouping itself under simple forms. These 

 first outlines, altered by time and circumstances, have succes- 

 sively given birth to radiated creatures, to the inferior molluscs, 

 the articulate animals, then the lowest fishes, then man. 



Here is a mistake, in our opinion ; if there exists (until we 

 know more) an immense and impassable difference somewhere 

 in the animal kingdom, it is between the vertebrate and the 

 invertebrate animals. Whilst the first show an admirable 

 unity of organic composition, the second do not seem to have 

 any at all, so that they do not admit of serial or linear classi- 

 fication. Each of the groups which they form is united by 

 some particularity to all the other groups, and naturalists hUve 

 even been able to differ about what must be considered as the 

 highest round in the animal ladder. The organism of the in- 

 vertebrata possesses a flexibility and immense variety, which 

 is almost a characteristic special to these beings in which the 

 nervous system ceases to present the profound unity which we 



* Vol. ii, second part, 1859. 



f Philosophic Zoologique, vol. i, p. 221. 



j Systeme des Connaissances Positives, p. 143, 1820. 



Discours de I' An XI, p. 45. He says, also, in another place (Philosophic 

 Zoologique, vol. i, p. 66), "What we call species, has only a relative constancy 

 in that state, and cannot be as ancient as nature itself." 



