68 ON THE ORIGIN OF SPECIES 



The elder de Candolle and Lyell have largely and philo- 

 sophically shown that all organic beings are exposed 

 to severe competition. In regard to plants, no one has 

 treated this subject with more spirit and ability than 

 W. Herbert, Dean of Manchester, evidently the result 

 of his great horticultural knowledge. Nothing is easier 

 than to admit in words the truth of the universal 

 struggle for life, or more difficult — at least I have found 

 it so — than constantly to bear this conclusion in mind. 

 Yet unless it be thoroughly engrained in the mind, I 

 am convinced that the whole economy of nature, with 

 every fact on distribution, rarity, abundance, extinction, 

 and variation, will be dimly seen or quite misunderstood. 

 We behold the face of nature bright with gladness, we 

 often see superabundance of food ; we do not see, or we 

 forget that the birds which are idly singing round us 

 mostly live on insects or seeds, and are thus constantly 

 destroying life ; or we forget how largely these songsters, 

 or their eggs, or their nestlings, are destroyed by birds 

 and beasts of prey ; we do not always bear in mind, 

 that though food may be now superabundant, it is not 

 so at all seasons of each recurring year. 



I should premise that I use the term Struggle for 

 Existence in a large and metaphorical sense, including 

 dependence of one being on another, and including 

 (which is more important) not only the life of the indi- 

 vidual, but success in leaving progeny. Two canine 

 animals in a time of dearth, may be truly said to 

 struggle with each other which shall get food and live. 

 But a plant on the edge of a desert is said to struggle 

 for life against the drought, though more properly it 

 should be said to be dependent on the moisture. A 

 plant which annually produces a thousand seeds, of 

 which on an average only one comes to maturity, may 

 be more truly said to struggle with the plants of the 

 same and other kinds which already clothe the ground. 

 The mistletoe is dependent on the apple and a few other 

 trees, but can only in a far-fetched sense be said to 

 struggle with these trees, for if too many of these para- 

 sites grow on the same tree, it will languish and dia. 



