astiff breed probably weigh nearly thirty times as
much as their smaller kinsmen. Great as are these variations, they are
only in form and bulk. They involve none of those curious changes in the
number of bones of the skeleton which we may trace among the
domesticated pigeons. We therefore turn from these results of breeders'
fancy to consider certain of the mental qualities of dogs which have not
come in our way in our review of the history of its relations to man.

First of all, we may note the fact that the friendly relations which
dogs have become accustomed to form with men vary exceedingly in their
range and activity. Perhaps in no other regard does the dog exhibit
such distinctly human characteristics as in the way in which he meets
the individuals of the mastering species. The gamut of their social
relations with men is almost exactly parallel with our own. With from
one to a dozen persons a dog may maintain an attitude of almost equally
complete sympathy and mutual understanding. He may be on terms of
acquaintanceship in varied degrees of familiarity with a few score
others with whom he comes in frequent contact. Toward the rest of
mankind he maintains a position of more or less complete distrust,
which with experience may attain the indifference which men commonly
show toward perfect strangers. If we observe a dog going along a
much-frequented street, we may note that his relations to the people
are substantially those which the folk have to each other. He shows as
they do a certain consideration for the individuals he encounters,
gives them their due place, and yet holds to his own. It is
particularly noticeable that he avoids all contact with the other
passers--in fact a dog has to be much beside himself with rage or fear,
or insane from disease, before he will break those bounds of
personality which civilization has set up to guide the conduct of life.

[Illustration: King Charles Spaniel]

The social culture of dogs appears to have gone to the point where
they recognize the meaning of an introduction--at least as far as the
sympathetic relations of that understanding are concerned. Almost any
well-bred dog will submit to be presented by his master, or even by
persons whom he knows but is not accustomed to obey, to a stranger to
whom he has already exhibited some dislike. During the introduction
he will submit to those formal exchanges of courtesy which he is
accustomed to recognize as the indices of frie