100 POPULAR SCRIPTURE ZOOLOGY.

effects of climate would be felt, and “it is probable that the
diminished size, and increased length and shagginess of the
hair,’which are seen in this and other species of mam- —
malia, when made to reside in countries much colder than
those which are natural to them, are connected with each
other ; and that that portion of the substance and action of
the animal which, in the cold climate, goes to the produc-
tion of the additional covering, would, in a more genial
climate, go to increase the size and flesh of the animal*.”
There is a peculiarity in the ass which distinguishes it
greatly from most domesticated animals, which is its inap-
titude for breaking into varieties, even those of colour.
Of the horse there are innumerable varieties, not merely of
colour, but of size, shape, and spirit, for not only has each
country its peculiar horse, but there are different kinds
adapted to almost every employment, so that the horse
appears particularly pliable to circumstances, whether of
climate or treatment. Many other domesticated animals
{the ox, for instance) are the same, but the ass shows no such
variations: there are trifling changes in colour, or rather
in shades of colour, but nothing more. “ Plastic animals,
which break into varieties adapted to different climates and

* British Cyolopeedi