362 The Bird 



who is suddenly forced to work at some arduous manual 

 labour, they have entered on new ways of life ways to 

 which their structure seems but ill adapted, and yet, 

 by the very daring of their efforts, they have won success. 



The great-grandfathers, many times removed, of the 

 modern Families of birds lived lives which were much 

 broader and more generalized than those of their descend- 

 ants of to-day, and it is this variety, this seeking of new 

 opportunities and overcoming of new difficulties by the 

 feathered sons, which makes the study of birds so fascinat- 

 ing a pursuit. 



Let us follow the diverging paths of the later gen- 

 erations of some of our own birds. Take the wood- 

 warblers of our own country. The only way we can 

 imagine what the earlier ancestors of the warblers were 

 like is to make a composite of the whole Family. All 

 its members are tiny, delicate birds which feed on the 

 smallest insects, their bills are slender and pointed, and 

 their feet and toes like the finest wire. Yet, far from 

 waiting for Nature to alter these delicate organs, they 

 have struck out boldly for themselves and, to avoid a 

 fatal competition with one another, have varied their 

 methods of hunting and the limits of their preserves so 

 successfully that a dozen may live in close proximity 

 and yet never poach on each other's domains. 



Our well-known little Maryland or Northern Yellow- 

 throat has chosen the low bushes of a marsh as his sphere 

 in life, and, although he has hidden his face behind a black 

 mask, yet he is a true warbler, and the blood of his fathers 

 forces him up now and then into some exposed position, 



