282 NATURAL HISTORY. 



at thirty years of age, and continues to produce offspring 

 till it is ninety years old, during which time it has six 

 young ones. The average age of the elephant may be 

 calculated at about one hundred years, though this is 

 often exceeded. On this basis, Darwin calculates that 

 at the end of about seven hundred and fifty years the 

 offspring of the first pair of elephants would amount 

 to about nineteen millions of then living individuals. 



(2) In consequence of this geometrical rate of increase 

 among all living beings, it necessarily follows that there 

 arises a ' Struggle for Existence' among animals and 

 plants. Each organism fills a certain place in the world 

 of nature, occupies a particular area, feeds on a particular 

 kind of food, requires, in short, a particular set of con- 

 ditions. As, however, every kind of animal and plant 

 is constantly bringing into the world more young than 

 can be accommodated, or for which suitable food can 

 be provided, it follows that there arises among the young 

 of each species a competition^ a struggle both for a proper 

 place and for proper food. This competition, which 

 is seen quite as much in plants as in animals, is what 

 is understood as the ' struggle for existence.' In using 

 this term, Darwin premises that he does so 'in a large 

 and metaphorical sense, including dependence of one 

 being on another, and including (what 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 

 the desert is said to struggle for life against the drought, 

 though more properly it should be said to be dependent 



