Vill Preface 
a bird’s foot. It is to bridge this gap that this book is 
intended—an untechnical study of the bird in the abstract. 
This, it seems to me, is the logical phase of bird life, 
which, with an earnest nature-lover, should follow the 
handbook of identification—the study of the physical 
life of the bird itself preceding the consequent phase 
of the mental life, with its ever-varying outward ex- 
pression. 
Far from considering this treatment exhaustive, one 
must remember that any chapter subject could easily 
be elaborated into one or more volumes. I have intended 
the book more as an invitation than aught else: for each 
to observe for himself the marvellously fascinating drama 
of evolution; to pass on from the nature stories of ideal- 
ized composite animals and birds to the consideration of 
the evolution of all life; to the tales of time and truth 
which have been patiently gleaned by the life-long labours 
of thousands of students. 
Whenever possible I have illustrated a fact with a 
photograph from a preparation or from a living bird, 
believing that, where verbal exposition fails, pictorial 
interest will often fix a fact in the memory. First of all 
we must consider a few of the more important and sig- 
nificant of the bird-forms of past ages; because no one 
who is interested in living birds from any standpoint 
should be entirely ignorant of a few facts concerning the 
ancestors of these creatures. Otherwise it is as if one, 
entirely ignoring the rest of the plant, studied certain 
leaves and flowers, knowing not whether they came from 
tree or vine. 
