THE STEUGGLE FOR EXISTENCE. 1 63 



that the number of adult individuals is limited by other 

 circumstances, especially by the relations in which the 

 organism stands to its organic and inorganic surroundings. 

 Every organism, from the commencement of its existence, 

 struggles with a number of hostile influences : it struggles 

 against animals which feed on it, and to which it is thenatm-al 

 food, against animals of prey and parasites ; it struggles 

 against inorganic influences of the most varied kinds, against 

 temperature, weather, and other circumstances ; but it also 

 struggles (and this is much the most important !), above all, 

 against organisms most like and akin to itself. Every 

 individual, of every animal and vegetable species, is engaged 

 in the fiercest competition with every other individual of 

 the same species which lives in the same place with it. In 

 the economy of natui'e the means of subsistence are 

 nowhere scattered in abundance, but are very limited, 

 and far from sufficient for the number of organisms which 

 might develop from the germs produced. Therefore the 

 young individuals of most species of animals and vegetables 

 must have hard work in obtaining the means of subsist- 

 ence ; this necessarily causes a competition among them in 

 order to obtain the indispensable supplies of life. 



This great competition for the necessaries of life goes on 

 everywhere and at all times, among human beings and 

 animals as well as among plants ; in the case of the latter 

 this circumstance, at first sight, is not so clearly apparent. 

 If we examine a field which is richly sown with wheat, 

 we can see that of the numerous young plants (perhaps 

 some thousands) which shoot up on a limited space, only a 

 very small proportion preserve themselves in life. A com- 

 petition takes place for the space of ground which each plant 



