THE TRANSMUTATION OF SPECIES. 251 



by spontaneous generation. Otherwise he thought that, in 

 the course of progressive modification, all the lowest forms 

 of living beings would long ere this have been ' improved 

 out of existence ' altogether. There is an interesting and 

 curious resemblance between the speculations of the 

 French philosopher on this and kindred subjects and the 

 notions which have been put forth by some writers even 

 in the last score of years. 



The subject of the agencies which are concerned in the 

 production of modifications in species was dealt with by 

 Lamarck in a most interesting chapter of the ' Philosophic 

 Zoologique,' 'on the influence of circumstances on the 

 actions and habitudes of animals, and of these actions and 

 habitudes as causes which modify the organisation and 

 structure of animals.' The title of this chapter will of 

 itself show that he regarded the general organisation of an 

 animal as, in the long run, the outcome and expression of 

 its actions and its habits ; and he regarded these latter as 

 the direct result of the animal's environment. Hence, in 

 investigating the causes which have led to the production 

 of 'species,' Lamarck began with a consideration of the 

 action of external conditions. 



It is an old and a natural idea that the organs of 

 animals were given to them for the purpose of adapting 

 them to the conditions under which they may happen to 

 be placed. Thus it is natural to the human mind to 

 think that the polar bear is white because it was created 

 to live among the snows of the Arctic regions; or that 

 the lion is tawny in colour because it is meant to live in 

 sandy deserts ; or that the long neck of the giraffe is a 

 pre-designed structure adapting it for feeding upon the 



