54 ZOOLOGICAL PHILOSOPHY 



will probably always evade our researches. This is rendered the more 

 likely since the enormous extent of water, its depth in many places, 

 and the prodigious fertihty of nature in the smallest species will doubt- 

 less be for all time an almost insuperable obstacle to the progress 

 of knowledge. 



A single class of the invertebrate animals, such as insects for instance, 

 equals the entire vegetable kingdom in the number and diversity of 

 its contained objects. The class of polyps is apparently much more 

 numerous still, but we shall never be able to flatter ourselves that 

 we know all the animals which make it up. 



As a result of the rapid multipUcation of the small species, and 

 particularly of the more imperfect animals, the multipUcity of in- 

 dividuals might have injurious effects upon the preservation of races, 

 upon the progress made in perfection of organisation, in short, upon 

 the general order, if nature had not taken precautions to restrain that 

 multipUcation within limits that can never be exceeded. 



Animals eat each other, except those which live only on plants ; 

 but these are liable to be devoured by carnivorous animals. 



We know that it is the stronger and the better equipped that eat 

 the weaker, and that the larger species devour the smaller. Neverthe- 

 less, individuals rarely eat others of the same race as themselves ; 

 they make war on different races. 



The multipUcation of the small species of animals is so great, and 

 the succession of generations is so rapid, that these small species would 

 render the globe uninhabitable to any others, if nature had not set 

 a Umit to their prodigious multiphcation. But since they serve 

 as prey to a multitude of other animals, and since the duration of 

 their hfe is very short and they are killed by any fall of temperature, 

 their numbers are always maintained in the proper proportions for 

 the preservation of their own and other races. 



As to the larger and stronger animals, they might well become 

 dominant and have bad effects upon the preservation of many other 

 races if they could multiply in too large proportions ; but their races 

 devour one another, and they only multiply slowly and few at a time ; 

 and this maintains in their case also the kind of equilibrium that 

 should exist. 



Lastly, man alone, considered apart from all that is special to him, 

 seems to be able to multiply indefinitely, for his intelligence and powers 

 protect him from any hmit of multiplication due to the voracity of 

 any animal. He exercises a supremacy over them, so that instead of 

 having to fear the larger and stronger races of animals, he is capable 

 rather of extinguishing them, and he is continually keeping down 

 their numbers. 



