A NATURALIST IN BRAZIL 



the surplus animals should be cruelly devoured? Might not Nature 

 have resembled a human machine, in which every least part is 

 precisely adapted as its position in relation to the whole demands? 

 Might not the animals have multiplied at such a rate as precisely 

 to fill the gaps made in their ranks by natural death? 



On considering the circumstances, we are at once impressed by 

 the great difference between the mechanism of Nature and the 

 machinery of man. The latter cannot be left to itself for decades at 

 a time; it would wear out, and it must therefore always be in the 

 charge of a technical expert. But the miraculous mechanism of 

 Nature has already run for countless ages of terrestrial history, 

 without even losing its energy; all the parts are still vigorous, and 

 any irregularity corrects itself. 



But if the worn-out parts are replaced by the mechanism itself, 

 every part of the latter must grow without ceasing, so that new 

 material is constantly introduced in the place of the old. It works, 

 and with it all its least parts, under an internal urge, and it is this 

 urge, this pressure, which finds expression in the reproduction of 

 animal life. Renovation without rejection of worn-out material is 

 impossible, and renovation must needs work with a surplus, in 

 order that it may have sufficient material in hand should there be 

 an abnormal call upon it. 



It is therefore an essential characteristic of the vital mechanism 

 of the earth that more animals are born than can ever live. But there 

 are still other intelligible reasons why so many creatures should 

 enter the world subject to the inevitable fate of being devoured or 

 of having to make room for others. So long as every living creature 

 does not attain its goal, so long as this is possible only for a small 

 minority, then, and only then, is there a competition in which each 

 strives to be a winner. In each generation, therefore, there is a 

 selection of the fittest, and only these succeed in bringing offspring 

 into the world, and these inherit only the qualities of the best of the 

 previous generation. On this process depends the increase of vital 

 energy and evolution in form. 



When the plane is used, shavings fall to the ground. The earth 

 must continually deck herself with new forms, and place must 

 always be made for them. Since in every geological epoch the 

 climate and soil of our planet undergo change, its animal inhabitants 

 must constantly be recast in new forms, and the old forms must not 

 be allowed to stand in their way. 



Lastly, we must not forget that the earth is no paradise. As in the 

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