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BIRD BOOK \ j j 



CHAPTER I. Structure and Flight 



SOME very practical-minded man has tersely 

 defined a bird as " an organism round, a 

 stomach," and it would be difficult to deny 

 that the gaining of its daily food is the prin- 

 cipal object a bird has in view, even if at a certain 

 period of the year it becomes secondary to the 

 instinct of propagating its own species. But in 

 gaining their livelihood birds are unconsciously 

 carrying out part of a great, far-reaching scheme 

 and help to preserve the balance of Nature. 

 They prey upon and consequently prevent the 

 undue multiplication of insects, which, if allowed 

 to increase without check, would ravage and 

 finally kill all trees. These in their turn would 

 be unable to perform their purifying functions on 

 the air which, we must suppose, would soon 

 become unfit for mankind to breathe. 



And how does man show his gratitude for 

 such services 1 In general he persecutes his bene- 

 factors for taking toll of the fruit, which, but for 

 them, he would be unable to cultivate and, still 

 worse, he has practically exterminated some of 

 the more brightly coloured species to gratify vanity. 

 A I 



