STRUGGLE FOR EXISTENCE 101 



Tlie 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 prop- 

 erly it should be said to be dependent on the moisture. 

 A plant which annually produces a thousand seeds, of 

 which only one of an average 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 languishes and dies. But 

 several seedling mistletoes, growing 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 oh 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. 



■^ - A^U^.»^ :W]a gig ^f!» \ f. 1 ^ ^ i^ ' Hw >** ■ ■ " ■ n LI m i ll I p w M^ i»i ii I ^ ng *-' 



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 



