30 PHYSICAL INVESTIGATION. 



it cannot, for instance, be refuted that the domesticated swine, 

 in spite of the different cranial form, belongs to the same 

 species as the wild boar, since in many parts of America the 

 imported swine have again returned to the type of the wild 

 boar. The considerably larger alimentary canal of the domestic 

 cat, compared with that of the wild cat, has, by some, been con- 

 sidered as a probable consequence of their food being more of 

 a vegetable kind, whilst others claim it as a proof of difference 

 of species. De Salles 1 expresses the argument of Blumen- 

 bach in the following terms : ' ' La domestication de Phomme, 

 oscillant perpetuellement entre les extremes de la civilisation 

 et Petat sauvage, doit avoir modifie Phomme encore plus pro- 

 fondement que les autres animaux domestiques." Man is 

 certainly, zoologically considered, pre-eminently a domestic 

 animal, and we cannot escape the conclusion that if the laws 

 of variation in animals also apply to him, the changes ex- 

 hibited by domestic animals in the torrid and frigid zones 

 must, by analogy, extend to man. 



On account of this analogy Nott and Gliddon (and recently 

 Giebel), following Morton, have endeavoured to prove that the 

 various canine races must be considered as specifically distinct : 

 and if this be conceded (as proved by the ancient Egyptian 

 monuments, in which the permanence of character is exhibited,) 

 the prolificacy of these between themselves weakens the dogma 

 of the unity of the human species ; for, ' ' zoologically speaking, 

 mankind and canidce occupy precisely the same position." 

 Although this proof can hardly be deemed sufficient to shake 

 the conclusions from the great number of examples adduced 

 by Blumenbach, it has this opposed to it : that others include 

 all the canidce in the same species because there exists 

 between them no fixed line of demarcation, the transitions of 

 their characters being manifold and perceptible, and their pro- 

 lificacy increasing by cross-breeding. 2 Nott, moreover, weakens 

 his own argument from analogy, by observing : 3 te Again and 

 again, in previous publications, I have alluded to the fallibility 



1 " Hist. Generate des Eaces Humaines," p. 265, 1849. 



2 Godron, " De FEspece et des Eaces/' p. 64, Nancy, 1848. 



3 Loc. cit., p. 402. 



