52 THE INFLUENCE OF INANIMATE SUEROUNDINGS. 



the two groups generally distributed over tte face of the earth. 

 "We know that its surface — dryland as well as land covered 

 with water — is capable of producing only a certain limited 

 number of plants, depending on the conditions of the locality. 

 Assuming then that a given number of plants — the maximum 

 number being present at the time — offered, let us say, a thou- 

 sand units of food to these two classes of animals, the car- 

 nivorous and herbivorous species would not be able to hare an 

 equal share of the space and of the food it would afford. The 

 flesh-eaters would only obtain food from the soil indirectly 

 through the plant- eaters. Now the ti-ansmutation of the nutri- 

 ment derived from the plants into the flesh of the plant-eaters 

 is inseparable from a certain loss in the whole mass, since the 

 oxidation of a certain amount of the organic constituents is 

 necessary for the production of animal heat and for the move- 

 ment and due use of all the functions of the body. Now we will 

 assume — quite arbitrarily — that the proportion of the whole 

 mass of plants produced by the soil is to the animals which can 

 subsist on them — converting them into animal tissue— as ten to 

 one ; then, in the area we have assumed, only 100 units of 

 feeders — ^individual Herbivorous animals — can live on 1 ,000 

 units of plant food. The maximum of noiirishment, then, which 

 exists for monophagous carnivorous animals, can amount only to 

 100 units. In the transmutation of these 100 units of food in 

 the organs of the Carnivora a considerable loss will be incurred; 

 organic matter will be consumed, the indigestible portions, as 

 hairs, hoofs, and horns, will be ejected, and if the proportions 

 were such that ten units of animal food could suffice only for 

 one unit of the animal body, the maximum of food as supplied 

 by 100 herbivorous animals would enable 10 carnivora at most 

 to exist. Thus the same area can never produce and maintain 

 so large a number of carnivorous as of herbivorous animals, an 

 inference which is perfectly confirmed by the facts. It is well 

 known that the number of Herbivora is much greater than 

 that of Carnivora; and in connection with this fact is this 

 other, that among the Vertebrata, those at any rate that com- 

 monly live in large herds, are vegetable feeders, while the indi- 

 vidual Carnivora, which are on the whole much less numerouSj 



