THE RANGE OF ANIMAL DIET 187 



and chickens. In the corn countries of the United 

 States the sparrow grows yearly more dependent on 

 grain, and less insectivorous than his European reputa- 

 tion justifies, and in this country two consecutive severe 

 winters made the tits take to bird-killing with an apti- 

 tude that shocked their patrons in English gardens. 

 Highly specialized forms, such as the ant-eaters, the 

 moles, and the leaf-eating sloths, must also of necessity 

 confine themselves to the food which they are ' by 

 intention ' adapted to consume. But even the wood- 

 pecker and the wryneck, with claws specially adapted 

 for scaling tree-trunks, and a beak formed to quarry 

 rotten wood, are constantly seen feeding on the ground, 

 mainly engaged in ravaging anthills ; and kingfishers, 

 scarcely modified from the shape of those which hover 

 over English streams, dart with equal precision on the 

 butterflies and beetles of tropical woods. Judging by 

 the scarcity of the l single-food ' creatures, and the low 

 place in the scale which they occupy, extension of the 

 range of diet is almost a necessary law of their survival. 

 Ant-eaters, sloths, and caterpillars may confine them- 

 selves to one article of food ; but the more intelligent 

 animals, like the higher races of man, have learnt better. 

 One almost wonders whether the excuse of the Congo 

 tribe who brought no palm-wine to the Belgian officers 

 was true. They alleged that the elephants had drunk 

 it all. 



