Introduction 
How clear the story is when once it has been pointed out! 
And we feel that in studying the marks of his presence we 
have learned something of the bear himself. 
Tracks on the snow are much easier hieroglyphs to decipher; 
to use Burrough’s words: ‘‘The snow is a great tell-tale and 
blabs as effectually as it obliterates. I go into the woods and 
know all that has happened. I cross the field, and if only a 
mouse has visited his neighbour, the fact is chronicled.” It is, 
indeed, a fascinating task to read the story of the mammals in 
the snow, to learn to know the sharp clear-cut trail of the fox, 
the blurred mark of the rabbit’s hairy foot, the nervous tread 
of the squirrels and the dainty traceries of the mice and shrews. 
A knowledge of mammals doubles the interest of an ordinary 
ramble to the lover of nature. Even though we see but few, 
we learn to know their presence and see their work on every 
side, and the more we learn of their ways the more frequent 
glimpses we get of them. 
The pleasure of seeing and studying a wild animal in life 
to me far outranks the gratification of making a good shot and 
‘bagging my game,” and | think that if the pleasure men feel in 
hunting were carefully analyzed it will be found that besides 
being close to nature it rests largely in the contest of skill and 
craft between hunter and game and that the mere killing is any- 
thing but a gratification. 
Structure and Classification 
Mammals form one of the great classes of vertebrate animals. 
The most important character which they have in common, but 
which is not possessed by any other animals, is that the young 
are nourished for some time after birth on milk secreted by the 
mother. Furthermore, all mammals are covered with more or less 
hair* in distinction to the feathers of birds, and the scales of fishes 
and reptiles. 
Mammals are supposed to have originated from some early 
reptilian animal and branched off long before the birds were 
evolved. They first became abundantly distributed over the Ter. 
tiary period though the earliest remains occur in the Triassic. 
* Entirely disappears in adult whales. 
xV 
