II THE ORIGIN OF SPECIES 67 



the purpose in view. It is a physiological fact, 

 he says, that organs are increased in size by 

 action, atrophied by inaction ; it is another 

 physiological fact that modifications produced are 

 transmissible to offspring. Change the actions of 

 an animal, therefore, and you will change its 

 structure, by increasing the development of the 

 parts newly brought into use and by the diminu- 

 tion of those less used; but by altering the 

 circumstances which surround it you will alter its 

 actions, and hence, in the long run, change of 

 circumstance must produce change of organisation. 

 All the species of animals, therefore, are, in 

 Lamarck's view, the result of the indirect action 

 of changes of circumstance, upon those primitive 

 germs which he considered to have originally 

 arisen, by spontaneous generation, within the 

 waters of the globe. It is curious, however, that 

 Lamarck should insist so strongly x as he has done, 

 that circumstances never in any degree directly 

 modify the form or the organisation of animals, 

 but only operate by changing their wants and 

 consequently their actions ; Tor he thereby brings 

 upon himself the obvious question, How, then, do 

 plants, which cannot be said to have wants or 

 actions, become modified ? To this he replies, 

 that they are modified by the changes in their 

 nutritive processes, which are effected by changing 

 circumstances ; and it does not seem to have 



1 See Phil. Zoologiquc, vol. i. p. 222, et seq. 



