many more evidences showing the animals' love of home, and that they
also know the meaning of home-sickness.

Not a few animals have learned definitely to lay out and obtain
recognition for the boundaries of their respective ranging-grounds. This
is amply proven by their respect and recognition of rights of way.
Animals of certain farms seem to know the exact boundaries of their
grazing lands and pastures, and to teach this knowledge to their young.
In addition they often police their lands and pastures against
intruders. Woe unto any traveller found on the wrong highway! It is not
uncommon for the transgressor to be pushed from a right of way to the
rocks below. More than once a court's decision regarding disputable
territory has been based on the sheep's recognition of boundary; those
sheep slain in battle or otherwise injured while trying to invade the
questionable territory have been paid for by the owner of the
transgressing sheep.

It is easy to understand how sheep can recognise their rights of way,
but somewhat difficult to account for their knowledge of boundaries.
Sheep and goats have for ages been the greatest mountain-path and
road-makers. Whether or not they have engineers, we are not sure, but
they seem to select the shortest, easiest, and best route across the
trackless hills, and never seem to change the way. In these localities,
the sheep are almost in a primitive condition, and "not the least
interesting feature of their conduct in this relapse to the wild life is
that, in spite of the highly artificial condition in which they live
to-day, they retain the primitive instincts of their race."

That this "peremptory and path-keeping" instinct is shown by the habits
of the musk-ox, is clear. He is as much akin to the sheep as to cattle,
and in habits more like those of the great prehistoric sheep as we
imagine these to have been. The musk-ox naturally assembles in large
flocks, and is migratory, just as the domesticated flocks of Spain are,
and those of Thrace and the Caspian steppe. These flocks always return
from the barren lands in the far north by the same road, and cross
rivers by the same fords. Nothing but too persistent slaughter at these
points by the enemies who beset them, induces them to desert their
ancient highways. Pictures and anecdotes of the migrations of these
animals, and of the bison in former days, represent them as moving on a
broad front across the prairie or tundra. The examples