14 On Some Interactions of Organisms. 



proved favorable to their native predecessors. But in the 

 grain-field and fruit-garden the case is different. Not 

 only do we bring in species often very unlike any aborig- 

 inal vegetation and still further altered by long cultiva- 

 tion, but we propose an end quite different from that for 

 whose accomplishment all the arrangements of Nature 

 have been made. 



According to the settled order, the whole economy of 

 every fully-established plant and animal is directed to the 

 production of one more plant or animal to take the place 

 of the first one when it perishes. All the excess of growth 

 and reproduction is a reward to friends or a tribute to pow- 

 erful enemies, intended to make only this one end secure. 

 But man is not content with this. He does not raise ap- 

 ple-trees for the sake of raising more apple-trees. He 

 would cut off all excess not useful to himself, and all that 

 is useful he would stimulate to the utmost, and appropri. 

 ate to his own benefit. In carrying out this purpose he 

 finds himself opposed and harassed at every step by rules 

 and customs of the natural world established long ages be- 

 fore he was seen upon the earth, — laws certainly too pow- 

 erful for him wholly to defy, customs too deeply rooted for 

 him to overturn without the most complicated consequen- 

 ces. And yet even here, we see that the primitive order is 

 not an evil, it is simply insufficient. It is good as far as 

 it goes, and must be carefully respected in its essence, 

 however far it may be modified in detail. We find abun- 

 dant reason for a belief in its usual beneficence and for a 

 reluctance to disturb it without urgent necessity. 



At the best the disturbances we must originate will be 

 tremendous. Old combinations will necessarily be broken 

 up and new ones entered into. As in a country undergoing 

 a radical change in its form of government, disorders will 

 almost certainly break out, — some of them fearfully de- 

 structive and temporarily uncontrollable ; but the general 

 tendency towards a just equilibrium will make itself felt, 

 and intelligent effort will mitigate some evils and avoid 

 others. Without attempting to go into details, — which 

 would be quite unnecessary for my purpose, — I will en- 



