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 (1/1. Owen 'British Fossil Mammals'
pages 123 to 133. Pictet 'Traite de Pal.' 1853 tome 1 page 202. De
Blainville in his 'Osteographie, Canidae' page 142 has largely discussed
the whole subject, and concludes that the extinct parent of all
domesticated dogs came nearest to the wolf in organisation, and to the
jackal in habits. See also Boyd Dawkins, 'Cave Hunting' 1874 page 131 etc.
and his other publications. Jeitteles has discussed in great detail the
character of the breeds of pre-historic dogs: 'Die vorgeschichtlichen
Alterthumer der Stadt Olmutz' II. Theil, 1872 page 44 to end.) 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 jackals,
and owing, on the other hand, to the great dissimilarity of the skulls of
the several breeds of the domestic dogs. It seems, however, that remains
have been found in the later tertiary deposits more like those of a large
dog than of a wolf, which favours the belief of De Blainville that our dogs
are the descendants of a single extinct species. On the other hand, some