Esquimaux, like other Arctic animals, extend round the whole polar
regions. It should be observed that the amount of difference between
the mammals of the several zoological provinces does not correspond
with the degree of separation between the latter; so that it can hardly
be considered as an anomaly that the Negro differs more, and the
American much less from the other races of man, than do the mammals of
the African and American continents from the mammals of the other
provinces. Man, it may be added, does not appear to have aboriginally
inhabited any oceanic island; and in this respect, he resembles the
other members of his class.
In determining whether the supposed varieties of the same kind of
domestic animal should be ranked as such, or as specifically distinct,
that is, whether any of them are descended from distinct wild species,
every naturalist would lay much stress on the fact of their external
parasites being specifically distinct. All the more stress would be
laid on this fact, as it would be an exceptional one; for I am informed
by Mr. Denny that the most different kinds of dogs, fowls, and pigeons,
in England, are infested by the same species of Pediculi or lice. Now
Mr. A. Murray has carefully examined the Pediculi collected in
different countries from the different races of man (8. Transactions
of the Royal Society of Edinburgh, vol. xxii, 1861, p. 567.); and he
finds that they differ, not only in colour, but in the structure of
their claws and limbs. In every case in which many specimens were
obtained the differences were constant. The surgeon of a whaling ship
in the Pacific assured me that when the Pediculi, with which some
Sandwich Islanders on board swarmed, strayed on to the bodies of the
English sailors, they died in the course of three or four days. These
Pediculi were darker coloured, and appeared different from those proper
to the natives of Chiloe in South America, of which he gave me
specimens. These, again, appeared larger and much softer than European
lice. Mr. Murray procured four kinds from Africa, namely, from the
Negroes of the Eastern and Western coasts, from the Hottentots and
Kaffirs; two kinds from the natives of Australia; two from North and
two from South America. In these latter cases it may be presumed that
the Pediculi came from natives inhabiting different districts. With
insects slight structural differences, if constant, are generally
esteemed of specific value: and the fact of the races of man being
infested by parasites, which appear to be specifically distinct, might
fairly be urged as an argument that the races themselves ought to be
188