202 



NATURE'S CALENDAR 



December 14 



Such a change of feathers or fur to 

 white may be helpful in two ways. First, 

 it no doubt tends to an increase of 

 warmth, the white hair preventing loss of 

 heat better than the more absorbent black 

 hair. A more important service, however, 

 is the concealment the colorlessness of 

 the animal affords it in a world of white, 

 where any creature of a dark color would 

 be conspicuous to its enemies a long dis- 

 tance oflf. 



A suggestive note on this point occurs 

 in Little Beasts of Field and Wood, by 

 William E. Cram, who says : 



" Late in the autumn, or earl)' in the 

 winter, the ermine changes from reddish 

 brown to white, sometimes slightly washed 

 with greenish yellow or cream color, and 

 again as brilliantly white as anything in 

 nature or art; the end of the tail, how- 

 ever, remains intensely black, and at first 

 thought might be supposed to make the 

 animal conspicuous on the white back- 

 ground of snow, but in reality has just the 

 opposite efTect. Place an ermine on new- 

 fallen snow in such a way that it casts no 

 shadow, and you will find that the black 

 point holds your ejG in spite of yourself, 

 and that at a little distance it is quite 

 impossible to follow the outline of the 

 weasel itself. Cover the tail with snow 

 and you can begin to make out the 

 position of the rest of the animal ; but as 

 long as the tip of the tail is in sight you 

 see that and that only." 



December 15 



