THE TRAGEDIES OF THE NESTS. 95 



hole, and seeing the farmer, checked his course and 

 darted back. The rats had doubtless turned to give 

 him fight, and would probably have been a match for 

 him. 



The weasel seems to track its game by scent. A 

 hunter of my acquaintance was one day sitting in the 

 woods, when he saw a red squirrel run with great 

 speed up a tree near him, and out upon a long branch, 

 from which he leaped to some rocks, and disappeared 

 beneath them. In a moment a weasel came in full 

 course upon his trail, ran up the tree, then out along 

 the branch, from the end of which he leaped to the 

 rocks as the squirrel did, and plunged beneath them. 



Doubtless the squirrel fell a prey to him. The 

 squirrel's best game would have been to have kept to 

 the higher tree-tops, where he could easily have dis- 

 tanced the weasel. But beneath the rocks he stood a 

 very poor chance. I have often wondered what keeps 

 such an animal as the weasel in check, for they are 

 quite rare. They never need go hungry, for rats and 

 squirrels and mice and birds are everywhere. They 

 probably do not fall a prey to any other animal, and 

 very rarely to man. But the circumstances or agen- 

 cies that check the increase of any species of animal 

 or bird are, as Darwin says, very obscure and but 

 little known. 



