Dogs after voiding their excrement often make with all four
feet a few scratches backwards, even on a bare stone pavement,
as if for the purpose of covering up their excrement
with earth, in nearly the same manner as do cats.
Wolves and jackals behave in the Zoological Gardens in exactly
the same manner, yet, as I am assured by the keepers,
neither wolves, jackals, nor foxes, when they have the means
of doing so, ever cover up their excrement, any more than do dogs.
All these animals, however, bury superfluous food. Hence, if we
rightly understand the meaning of the above cat-like habit,
of which there can be little doubt, we have a purposeless remnant
of an habitual movement, which was originally followed by some
remote progenitor of the dog-genus for a definite purpose,
and which has been retained for a prodigious length of time.

Dogs and jackals[15] take much pleasure in rolling and
rubbing their necks and backs on carrion. The odour seems
delightful to them, though dogs at least do not eat carrion.
Mr. Bartlett has observed wolves for me, and has given them carrion,
but has never seen them roll on it. I have heard it remarked,
and I believe it to be true, that the larger dogs, which are
probably descended from wolves, do not so often roll in carrion
as do smaller dogs, which are probably descended from jackals.
When a piece of brown biscuit is offered to a terrier of mine
and she is not hungry (and I have heard of similar instances),
she first tosses it about and worries it, as if it were a rat
or other prey; she then repeatedly rolls on it precisely as if it
were a piece of carrion, and at last eats it. It would appear
that an imaginary relish has to be given to the distasteful morsel;