48 DARWINISM AND THE PROBLEMS OF LIFE 



species leads to an increase in the number of its 

 enemies. Moreover, it often happens that a dispro- 

 portionate spread of any particular species carries its 

 own corrective with it ; the animals show symptoms 

 of disease, and die off suddenly as if by magic. This 

 was seen, for instance, during the great plague of mice 

 on the Rhine in the twenties ; and the plague of black- 

 arches at the beginning of the nineties also came to a 

 sudden stop. 



It is true that the injury already done by these swarms 

 of pests is so great that men are not disposed to wait for 

 the end, but make every effort to check their progress. 

 But it is otherwise with animals which cannot multiply 

 in this extraordinary way. These should be spared, I 

 think, even if they do a little damage here and there. 



Just as we protect singing birds for their song, we 

 should also try to preserve animals that afford pleasure 

 to the eye. We ought to forgive the squirrel his taste 

 for bird's eggs, or even for the callow young, for we 

 should greatly miss this graceful animal, the ape of our 

 forests, if he ceased to enliven our trees. What does it 

 really matter if the kingfisher does destroy a few fishes 

 a day and generally fishes that are no use to us ! He 

 makes up for that by his beautiful appearance. How 

 sad it would be if we were to lose for ever the unfor- 

 gettable moments that come to the solitary dreamer by 

 the stream when he catches sight of this bird with its 

 plumage of jewels ! What an impiety to shoot a stork 

 because he has stolen a young hare ! When we were 

 children the stork was almost a sacred bird to us with 

 his inexhaustible poetry. Let us leave him such to 



