of long-continued civilisation.

[The number of breeds and sub-breeds of the dog is great; Youatt for
instance, describes twelve kinds of greyhounds. I will not attempt to
enumerate or describe the varieties, for we cannot discriminate how much of
their difference is due to variation, and how much to descent from
different aboriginal stocks. But it may be worth while briefly to mention
some points. Commencing with the skull, Cuvier has admitted (1/54. Quoted
by I. Geoffroy 'Hist. Nat. Gen.' tome 3 page 453.) that in form the
differences are "plus fortes que celles d'aucunes especes sauvages d'un
meme genre naturel." The proportions of the different bones; the curvature
of the lower jaw, the position of the condyles with respect to the plane of
the teeth (on which F. Cuvier founded his classification), and in mastiffs
the shape of its posterior branch; the shape of the zygomatic arch, and of
the temporal fossae; the position of the occiput--all vary considerably.
(1/55. F. Cuvier in 'Annales du Museum' tome 18 page 337; Godron 'De
l'Espece' tome 1 page 342; and Col. H. Smith in 'Nat. Library' volume 9
page 101. See also some observations on the degeneracy of the skull in
certain breeds, by Prof. Bianconi 'La Theorie Darwinienne' 1874 page 279.)
The difference in size between the brains of dogs belonging to large and
small breeds "is something prodigious." "Some dogs' brains are high and
rounded, while others are low, long, and narrow in front." In the latter,
"the olfactory lobes are visible for about half their extent, when the
brain is seen from above, but they are wholly concealed by the hemispheres
in other breeds." (1/56. Dr. Burt Wilder 'American Assoc. Advancement of
Science' 1873 pages 236, 239.) The dog has properly six pairs of molar
teeth in the upper jaw, and seven in the lower; but several naturalists
have seen not rarely an additional pair in the upper jaw (1/57. Isid.
Geoffroy Saint-Hilaire 'Hist. des Anomalies' 1832 tome 1 page 660, Gervais
'Hist. Nat. des Mammiferes' tome 2 1855 page 66. De Blainville