A SQUIRREL'S NEST. 91 



life. We can hardly regard it as a habit derived from a 

 single common ancestor, because it appears so sporadi- 

 cally, and so many related species are wholly wanting in 

 it. Most probably it has been independently evolved in 

 the squirrel, the harvest-mouse, the rat, the field-mouse, 

 and the beaver, from the fact that in each group alike 

 those who manifested it most would always best survive 

 through the chilly and foodless northern winters. On 

 the other hand, the storing instinct is sometimes replaced 

 among allied animals by other instincts almost equally 

 remarkable : as in the case of the dormouse, who gets 

 over the same difiiculty by fattening himself inordinately 

 during the summer, and then sleeping away the winter 

 so as only to use up the irreducible minimum of food- 

 stuffs in the absolutely indispensable vital actions of the 

 heart and lungs. From the point of view of mere sur- 

 vival, it would matter little whether any particular 

 group happened to fall into the one practice or the 

 other. It is very noticeable, however, that while the 

 sleepiness of the dormouse has fostered, or at least has 

 not militated against, a stupidity as great as that of the 

 guinea-pig or the tame rabbit, the more active and prov- 

 ident habits of the squirrel and the beaver have fostered 

 an amount of intelligence extremely rare among rodents, 

 or, indeed, among animals generally. I once kept a 

 tame squirrel for some months, not in a wretched little 

 tread-mill cage, but loose in my rooms ; and in affection- 

 ateness of demeanor, as well as in general cleverness of 

 perceptions, it certainly surpassed a good many dogs that 

 I have known. Doubtless the habit of storing food grew 

 up at first, as the west-country proverb says, more by 

 hap than cunning. It may have originated merely from 

 the thoughtlessly greedy practice of carrying home more 

 food at a time than was needed for immediate consump- 



