ere found for the peculiar capacities of the
creature. These varied in the different parts of the world, according
to the peculiarities in the conditions of the masters. In high
latitudes, where the ground is snow-covered during the winter season,
dogs were used, as they are to this day, in dragging sleds. They were,
indeed, perhaps the first animals which were harnessed to vehicles. When
they were brought to serve this definite end, we may well believe that
the stronger and more enduring individuals were spared in times of
dearth for the reason that they were almost indispensable to their
masters, and even the little forethought which we find among primitive
peoples would lead to their preservation. Here again, doubtless, came in
the process of unintended selection which has made the Esquimau sled-dog
one of the most remarkable varieties of his kind.

Perhaps the most interesting of the early variations induced among
dogs is that which has arisen from the pastoral habit. We do not know
when this custom of keeping sheep in large flocks was first
instituted, but it is evidently of exceeding antiquity, probably far
older than the pyramids of Egypt. The custom could hardly have been
instituted without help of the shepherd's mate, the sheep-dog.
Although the creatures of this breed are probably in form very near to
the original wild species whence our canines came, the variety has as
regards its instincts been, by a process of education and selection,
led very far away from the original stock.

The wild forefathers of this species were clearly natural born
sheep-slayers, and the motive abides to this day in all the breeds which
have the strength to assail our unresisting flocks. The spirit is so
ingrained that even the most civilized of our house-dogs, which may for
generations never have tasted blood and which show no disposition to
attack the other animals of the barn-yard, cannot be trusted alone with
sheep. When two or more of them are together the old instincts of the
wild pack return, and they will slay with insensate brutality until they
are fairly exhausted with their fury. Their behavior on such occasions
reminds one of the actions of their masters when possessed with the
blind rage of a mob. Yet in the shepherd-dog we find this ancestral
motive, once a large part of the life of the creature, so overcome by
education and selection that they will not only care for a flock with
all the devotion which self-interest c