THR RACES OF MAN. 193 



range throughout the Continent; and this at first appears 

 opposed to the above rule, for most of the productions of 

 the Southern and Northern halves differ widely; yet some 

 few living forms, as the ojjossum, range from the one into 

 the other, as did formerly some of the gigantic Edentata. 

 The Esquimaux, like other xerotic 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 con- 

 sidered as an anomaly that the Xegro 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 in- 

 formed 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 coun- 

 tries from the different races of man;* and he finds that 

 they differ, not only in color, 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 sailoi*s 

 they died in the course of three or four days. These Pedi- 

 culi were darker colored and appeared different from those 

 proper to the natives of Chili, 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 



* "Transact. R. Soc. of Edinburgh," vol. xxii, 1861, p. 567. 



