DARWIN. 67 



Geoffrey Saint Hilaire in France, came independently to 

 similar conclusions as to the mutability of species ; and 

 Lamarck followed with several well-known works in 

 1801-15, in which he upholds the doctrine that all species, 

 including man, are descended from other species. As 

 Darwin says, Lamarck 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. He saw 

 the difficulty of distinguishing between species and 

 varieties, the almost perfect gradation of form in some 

 groups, and the great similarity of domestic breeds of 

 animals to such species. He believed that some degree 

 of change was produced by the physical conditions of 

 life, the intercrossing of species, and by habits causing 

 increased use or disuse of parts. Indeed he thought 

 very many remarkable adaptations, such as that of the 

 neck of the giraffe for browsing on trees, were the effect 

 of habit. But he attributed, perhaps, more to a law of 

 progressive development impressed on all forms of life, 



perpetual endeavour of the creatures to supply the want of food, 

 and to have been delivered to their posterity with constant improve- 

 ment of them for the purpose required. . . . The third great want 

 among animals is that of security, which seems much to have 

 diversified the forms of their bodies and the colour of them. . . . 

 The contrivances for the purposes of security extend even to vege- 

 tables. . . . Would it be too bold to imagine that in the great 

 length of time since the earth began to exist ... all warm-blooded 

 animals have arisen from one living filament, which the Great First 

 Cause endued with animality ; . . . possessing the faculty of con- 

 tinuing to improve by its own inherent activity, and of delivering 

 down those improvements by generation to its posterity, world 

 without end ! " 



