setters, born in India, which perfectly resembled their Scotch parents: he
raised several litters from them in Delhi, taking the most stringent
precautions to prevent a cross, but he never succeeded, though this was
only the second generation in India, in obtaining a single young dog like
its parents in size or make; their nostrils were more contracted, their
noses more pointed, their size inferior, and their limbs more slender. So
again on the coast of Guinea, dogs, according to Bosman, "alter strangely;
their ears grow long and stiff like those of foxes, to which colour they
also incline, so that in three or four years, they degenerate into very
ugly creatures; and in three or four broods their barking turns into a
howl." (1/76. A. Murray gives this passage in his 'Geographical
Distribution of Mammals' 4to 1866 page 8.) This remarkable tendency to
rapid deterioration in European dogs subjected to the climate of India and
Africa, may be largely accounted for by reversion to a primordial condition
which many animals exhibit, as we shall hereafter see, when their
constitutions are in any way disturbed.

Some of the peculiarities characteristic of the several breeds of the dog
have probably arisen suddenly, and, though strictly inherited, may be
called monstrosities; for instance, the shape of the legs and body in the
turnspit of Europe and India; the shape of the head and the under-hanging
jaw in the bull-and pug-dog, so alike in this one respect and so unlike in
all others. A peculiarity suddenly arising, and therefore in one sense
deserving to be called a monstrosity, may, however, be increased and fixed
by man's selection. We can hardly doubt that long-continued training, as
with the greyhound in coursing hares, as with water-dogs in swimming--and
the want of exercise, in the case of lapdogs--must have produced some
direct effect on their structure and instincts. But we shall immediately
see that the most potent cause of change has probably been the selection,
both methodical and unconscious, of slight individual differences,--the