we are. If
we are much more ignorant than is generally supposed, most of these
difficulties wholly disappear. Let the reader reflect on the difficulty of
looking at whole classes of facts from a new point of view. Let him observe
how slowly, but surely, the noble views of Lyell on the gradual changes now
in progress on the earth's surface have been accepted as sufficient to
account for all that we see in its past history. The present action of
natural selection may seem more or less probable; but I believe in the
truth of the theory, {14} because it collects under one point of view, and
gives a rational explanation of, many apparently independent classes of
facts.[4]

* * * * *

{15}

CHAPTER I.

DOMESTIC DOGS AND CATS.

ANCIENT VARIETIES OF THE DOG--RESEMBLANCE OF DOMESTIC DOGS IN VARIOUS
COUNTRIES TO NATIVE CANINE SPECIES--ANIMALS NOT ACQUAINTED WITH MAN AT
FIRST FEARLESS--DOGS RESEMBLING WOLVES AND JACKALS--HABIT OF BARKING
ACQUIRED AND LOST--FERAL DOGS--TAN-COLOURED EYE-SPOTS PERIOD OF
GESTATION--OFFENSIVE ODOUR--FERTILITY OF THE RACES WHEN
CROSSED--DIFFERENCES IN THE SEVERAL RACES IN PART DUE TO DESCENT FROM
DISTINCT SPECIES--DIFFERENCES IN THE SKULL AND TEETH--DIFFERENCES IN
THE BODY, IN CONSTITUTION--FEW IMPORTANT DIFFERENCES HAVE BEEN FIXED BY
SELECTION--DIRECT ACTION OF CLIMATE--WATER-DOGS WITH PALMATED
FEET--HISTORY OF THE CHANGES WHICH CERTAIN ENGLISH RACES OF THE DOG
HAVE GRADUALLY UNDERGONE THROUGH SELECTION--EXTINCTION OF THE LESS
IMPROVED SUB-BREEDS.

CATS, CROSSED WITH SEVERAL SPECIES--DIFFERENT BREEDS FOUND ONLY IN
SEPARATED COUNTRIES--DIRECT EFFECTS OF THE CONDITIONS OF LIFE--FERAL
CATS--INDIVIDUAL VARIABILITY.

The first and chief point of interest in this chapter is, whether the
numerous domesticated varieties of the dog have descended from a single
wild species, or from several. Some authors believe that all have descended
from the wolf, or from the jackal, or from an unknown and extinct species.
Others again believe, and this of late has been the favourite tenet, that
they have descended from several species, extinct and recent, more or less
commingled together. We shall probably never be able to ascertain their
origin with certainty. Palaeontology[5] does not throw much light on the
question, owing, on the one hand, to the close similarity of the skulls of
extinct as well as living wolves and jac