164 FROM LAMARCK TO ST. NIL A IRE. 



edge necessary to establish it. In consideration of this gradation 

 of life, there are only two conclusions which face us as to its 

 origin : — The cofic/iisiofi adopted up to to-day : Nature (or its 

 Author) in creating animals has foreseen all possible sorts of cir- 

 cumstances in which they would be destined to live, and has given 

 to each species a constant organization, as well as a form deter- 

 mined and invariable in its parts, which forces each species to live 

 in the places and climates where it is found, and there to preserve 

 the habits which we know belong to it. My personal conclusion : 

 Nature, in producing successively all the species of animals, and 

 commencing by the most imperfect or the most simple to con- 

 clude its labour in the most perfect, has gradually completed their 

 organization ; and of these animals, while spreading generally in 

 all the habitable regions of the globe, each species has received, 

 under the influence of environment which it has encountered, the 

 habits which we recognize and the modifications in its parts which 

 observation reveals in it." 



The first conclusion (Special Creation), he goes 

 on to say, is one which has been held by nearly 

 every one up to the present time. It attributes to 

 each animal a constancy of structure, and parts 

 which have never varied and will never vary. To 

 disprove the second conclusion (Evolution), he con- 

 tinues, it is necessary to prove, first, that each point 

 upon the surface of the globe never varies in its 

 nature, climate, exposure, elevation, and so forth. 



The belief in the uniformity of past and present 

 changes was the next great factor in the develop- 

 ment of Lamarck's theory. It arose from his con- 

 templation of the data of Geology in connection 

 with those of Biology, as was afterwards the case 

 with Darwin, in so marked a degree. In Geology he 



