the period of the jackal has been found to be from sixty to sixty-three
days, exactly as with the dog.) Tessier, who 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 applies only to 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 (1/43. See Isid. Geoffroy St.-Hilaire 'Hist. Nat. Gen.' tome 3 page
112, on the odour of jackals. Col. Ham. Smith in 'Nat. Lib.' volume 10 page
289.); 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 dog is more
odoriferous than other dogs. Isidore Geoffroy (1/44. Quoted by Quatrefages
in 'Bull. Soc. d'Acclimat.' May 11, 1863.) gave to a dog the same odour as
that from a jackal by feeding it on raw flesh.

The belief that our dogs are descended from wolves, jackals, South American
Canidae, and other species, suggests a far more important difficulty. These
animals in their undomesticated state, judging from a widely-spread
analogy, would have been in some degree sterile if intercrossed; and such
sterility will be admitted as almost certain by all those who believe that