eria has an argali,
that appears altogether to differ from the argali of the Himalayas.
Again, in the Himalayan Mountains themselves, there is one species which
ranges north only as far as Thibet; while on the Thibetian plateaux, as
far as the Altai Mountains, there is another, if not two other species,
quite distinct from the latter.

It has been observed by competent travellers, that these Thibetian
argalis bear a very strong resemblance to the different breeds of tame
sheep found in the same regions; from which it may be reasonably
inferred that the domesticated varieties of different countries have
sprung from several wild species, instead of being all descended from
one common origin.

CHAPTER TWENTY.

GOATS.

My young readers will be surprised to hear that nothing is more
difficult than to tell a _Goat_ from a _Sheep_. Yet such is in reality
the fact. Of course the common goat is easily distinguished from the
common sheep; but then there are species and varieties of both these
animals so like in shape, size, colour, and habits, that the most
accomplished naturalists are unable to pronounce which are goats and
which are sheep! Indeed, some naturalists make no distinction at all,
but class both under the same genus. This, however, is not a correct
view, since there is an essential difference in the _nature_ of these
two animals, notwithstanding the frequent resemblance in their outward
appearance. It was upon this very point--their _nature_--that the
renowned Buffon relied in separating them; he alleging that the sheep
differed only from the goats in the greater gentleness and timidity of
their disposition. It is true that this is not a very scientific mode
of classification; yet, strange to say, it is held to be one of the
safest guides for distinguishing the one from the other. Of course, it
can only be relied upon when taken in connection with other indices of a
physical character. Perhaps you may fancy that goats and sheep may be
distinguished from each other by the "coat"--the former having a _hairy_
coat, while that of the latter is _woolly_. For you who reside in the
British Islands, this mark would stand good enough, since British goats
are in reality clothed with hair, and British sheep with wool; but in
many other countries the case is not only different, but directly the
reverse, the goats being _woolly_, while the sheep are _hairy_!

It may be further remarked, that there are both goat