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, vet he is a true warbler, and the blood of his fathers 
forces him up now and then into some exposed position, 
