SO THE ORIGIN OF SPECIES 



though food may be now superabundant, it is not so at all seasons 

 of each recurring year. 



THE TERM, STRUGGLE FOR EXISTENCE, USED IN A LARGE SENSE 



I should premise that I use this term 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 individual, 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 only one of an aver- 

 age 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 parasites grow on the same 

 tree, it languishes and dies. But several seedling mistletoes, grow- 

 ing close together on the same branch, may more truly be said to 

 struggle with each other. As the mistletoe is disseminated by birds, 

 its existence depends on them; and it may metaphorically be said 

 to struggle with other fruit-bearing plants, in tempting the birds 

 to devour and thus disseminate its seeds. In these several senses, 

 which pass into each other, I use for convenience' sake the general 

 term of Struggle for Existence. 



GEOMETRICAL RATIO OF INCREASE 



A struggle for existence inevitably follows from the high rate 

 at which all organic beings tend to increase. Every being, which 

 during its natural lifetime produces several eggs or seeds, must 

 suffer destruction during some period of its life, and during some 

 season or occasional year; otherwise, on the principle of geo- 

 metrical increase, its numbers would quickly become so inordi- 

 nately great that no country could support the product. Hence, as 

 more individuals are produced than can possibly survive, there 

 must in every case be a struggle for existence, either one individual 

 with another of the same species, or with the individuals of dis- 

 tinct species, or with the physical conditions of life. It is the doc- 

 trine of Malthus applied with manifold force to the whole animal 

 and vegetable kingdoms; for in this case there can be no artificial 

 increase of food, and no prudential restraint from marriage. Al- 

 though some species may be now increasing, more or less rapidly, 



