28 LOST AND VANISHING BIRDS 



severe strain upon the imagination to picture a 

 time when all the larger wild birds and beasts, all 

 the exceptionally helpless ones of the earth, must 

 perish, or exist only as specimens in our museums, 

 or as phantom records in our scientific literature. 

 This will be a serious outlook for the biologist of 

 the future, and the matter has long been suflSciently 

 important to warrant some strong steps being 

 taken to avert as far as possible such a vast 

 calamity. After all, we only hold the fauna of 

 the world in trust, and it is but our bare duty 

 to posterity to hand that fauna down as intact as 

 we found it, or as nearly so as the reasonable 

 exigencies of life will admit. 



We now come to consider the question of exter- 

 mination in a partial sense, and more especially as 

 it relates to our own islands. The species with 

 which we are therefore concerned now are those 

 that have become extinct in some parts of their 

 range, although they still survive in other areas. 

 Here, again, islands present us with the most 

 significant and important instances of recent ex- 

 tinction, although many continental examples 

 might be cited where birds have been extirpated 

 in some localities although continuing to flourish 

 in others. The Passenger Pigeon of America and 



