34 THE STORY OF BIRD-LIFE, 



either for one of its own species, or for its own 

 mate. This ability to successfully mimic the 

 shrike has certainly proved of the greatest value 

 to the species. 



In the earlier part of this chapter we spoke of 

 the resemblance of certain birds to their normal 

 surroundings. This is called "adaptation to 

 environment." Concerning this we have a few 

 more words to say. 



A little reflection will call to .the readers' 

 mind the fact that most animals, e.g. : foxes, 

 hares, rabbits, most birds, reptiles and fish, 

 are of a darker colour above than below. The 

 great advantage of this has recently been most 

 successfully demonstrated at the British Museum 

 (Natural History), by means of a couple of 

 models prepared by Mr Thayer, of the United 

 States of America. It was done in this wise: 

 A large square box was lined with grey flannel, 

 and in it were placed two bird models which 

 were fastened to a rod running through the 

 middle of the box. Both of these dummies 

 were covered with flannel cut from the same 

 material as that used to line the box. One, 

 however, was painted dark above and white 

 below, the other was left uucoloured. Strange 

 to say, the uncoloured bird is most conspicuous ; 

 the painted bird, by counteracting the normal 

 light and shade, becomes, at two yards' distance, 

 almost absolutely invisible. 



Thus, then, we must altogether cease . to re- 

 gard the colours of animals as due to mere chance. 

 Whether gorgeous or plain, brilliant or dull, 

 there is a meanino; behind it. Of the truth of 



