o a
certain extent the above-given cases of correlation between the
eye-spots and the colour of the feet. Moreover, some jackals and foxes
have a trace of a white ring round their eyes, as in _C. mesomelas_,
_C. aureus_, and (judging from Colonel Ham. Smith's drawing) in _C.
alopex_ and _C. thaleb_. Other species have a trace of a black line
over the corners of the eyes, as in _C. variegatus_,
_cinereo-variegatus_, and _fulvus_, and the wild Dingo. Hence I am
inclined to conclude that a tendency for tan-coloured spots to appear
over the eyes in the various breeds of dogs, is analogous to the case
observed by Desmarest, namely, that when any white appears on a dog the
tip of the tail is always white, "de maniere a rappeler la tacho
terminale de meme couleur, qui caracterise la plupart des Canidees
sauvages."[44]

It has been objected that our domestic dogs cannot be descended from wolves
or jackals, because their periods of gestation are different. The supposed
difference rests on statements made by Buffon, Gilibert, Bechstein, and
others; but these are now known to be erroneous; and the period is found to
agree in the wolf, jackal, and dog, as closely as could be expected, for it
is often in some degree variable.[45] Tessier, who {30} has closely
attended to this subject, allows a difference of four days in the gestation
of the dog. The Rev. W. D. Fox has given me three carefully recorded cases
of retrievers, in which the bitch was put only once to the dog; and not
counting this day, but counting that of parturition, the periods were
fifty-nine, sixty-two, and sixty-seven days. The average period is
sixty-three days; but Bellingeri states that this holds good only with
large dogs; and that for small races it is from sixty to sixty-three days;
Mr. Eyton of Eyton, who has had much experience with dogs, also informs me
that the time is apt to be longer with large than with small dogs.

F. Cuvier has objected that the jackal would not have been domesticated on
account of its offensive smell; but savages are not sensitive in this
respect. The degree of odour, also, differs in the different kinds of
jackal;[46] and Colonel H. Smith makes a sectional division of the group
with one character dependent on not being offensive. On the other hand,
dogs--for instance, rough and smooth terriers--differ much in this respect;
and M. Godron states that the hairless so-called Turkish do