NATURE AS AN ORGANISM 



the final link of this chain? Must not their multiplication too be 

 controlled with all the rest, and in this case are not the controlling 

 enemies lacking? Well, in this case Nature has employed the other 

 method at her disposal: she has diminished the animal's power of 

 multiplication. The elephant fears nothing, and therefore multiplies 

 but slowly : the cow elephant carries her calf for twenty-two months, 

 and bears young only once in every two years. 



We see, then, that Nature can dispose of two methods of limiting 

 the numbers of an animal which seems likely to overtake the rest 

 and so disturb the equilibrium. She can increase the danger of its 

 destruction, or decrease its powers of multiplication. If we survey 

 the animal kingdom we see these two possibilities in every imaginable 

 degree of combination. The result, however, in the case of every 

 animal or vegetable species, is always this equation : The danger of 

 destruction stands in such a ratio to the coefficient of multiplication 

 that the species retains its place in the general ensemble. 



An animal diminishes the dangers of the destruction which threatens 

 it by holding its enemies at bay by means of mere strength, or the 

 use of special weapons, or by escaping them by the speed of its 

 flight, or by discovering a secure place of refuge, or by concealing 

 itself so effectively, by means of its colour and form, that it cannot 

 readily be detected. The large birds of prey produce only one or 

 two young at a time. But who threatens them, who can reach their 

 brood, safe in the highest tree-tops or on inaccessible precipices? 

 Above the shore of Olinda the black vultures float in the air all 

 day ; but their breeding-place is hundreds of miles inland. But what 

 is a distance of a few hundred miles to these proud navigators? 

 With a favouring wind it is soon covered, without even a flap of 

 the wings ! 



The small birds, as a general thing, lay five eggs, for they have 

 many enemies to fear, and those that nest on the ground lay even 

 more. Of the mammals, the Pacas, Capyvaras, Preyas, and par- 

 ticularly the mice, multiply exceedingly. But they are the chief prey 

 of most of the carnivorous birds and animals, and the much-persecuted 

 rodents could not make up for their constant losses save by almost 

 incredible fertility. 



The fish multiply even more vigorously. Many species produce 

 more than 100,000 eggs. In the water, however, the battle for 

 existence is waged in its most inexorable form. Almost every fish 

 hunts and swallows smaller fish; the eggs and young fry suffer 

 terrible losses ; larger fish which find their way into a shoal of fry 



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