Where did Life Begin? 51 



favorable conditions they have been going on 

 from bad to worse in a fierce struggle for 

 existence. 



Evolution and degeneration in the organic 

 world are, in one phase at least, the result of 

 changes in the counter relations of demand 

 and supply. Whenever In respect to the or- 

 ganism, and all things possibly useful to it, 

 the supply by the smallest degree exceeds 

 the demand, old wants and capacities are en- 

 larged, and new wants creep into existence; 

 therewith old organs are improved and new 

 ones developed for securing and appropriating 

 by defence, contest, and competition, this sur- 

 plus ; the organism thus acquires varied appe- 

 tites, increased activity, diversified employ- 

 ments, keener sensibilities, and a wider range 

 of life, and so passes by such changes from 

 the simpler to the more complex in form 

 and function — and this Is evolution. So, on the 

 other hand, when the demand is greater than 

 any available supply, the wants denied must 

 be suppressed; therewith the organs and ca- 

 pacities specialized for their gratification first 

 fall into disuse, are then atrophied, and thus 



