12 INTRODUCTION. 
been too much collecting by far, that has yielded 
nothing worth the knowing. It is not justifiable to 
kill a hundred warblers in a day just to see if a 
particular one was among them. There is nothing 
to be gained in determining that there are possible 
hybrids or, it may be, an overlooked good species 
found in a given area. Let what we do not know go 
unknown until discovered by accident, and let the 
birds live. Remember that it is true of every one of 
them, that— 
He who sings and flies away 
Lives to sing another day. 
When we take up the subject of birds and their 
place in Nature, we are brought face to face with that 
very technical, dry-as-dust matter, their classification. 
It is necessary to be methodical in considering them, 
and particularly so when we are concerned with 
groups rather than individuals; but whether we 
begin with a little brown diver and wind up with a 
thrush or vce versa does not matter so much. A 
glance merely at technical ornithology is sufficient to 
show that the biologists who have closely studied 
birds are not quite of one mind as to the positions 
the various groups should have in the class AVEs, 
Considering zoology as a whole, the most logical 
plan is to commence at the bottom, or lowest form, 
and proceed to the top, or highest form; and these, 
in North America, are represented by the diver and 
the thrush; but for personal convenience, and because 
the thrush is more widely known than the diver, we 
will reverse the plan, and starting with the birds that 
are the climax of avian development, glide leisurely 
