VARIETIES OP MANKIND. 451 



and females of all the varieties breed together readily and in per- 

 petuity,* an assertion which cannot be made in regard to any 

 different species of brutes. 



The cause of the differences of our species has been more or 

 less sought for in climate, alone or in conjunction with other 

 external circumstances, by Aristotle, Hippocrates, Cicero, Pliny, 

 Plutarch, Galen, nearly all the Greek and Roman historians and 

 poets, Montaigne, Montesquieu, Buffon, Zimmerman, Blumen- 

 bach, Dr. Smith of America, &c. Lord Kaimes has denied the 

 power of these circumstances to produce the diversities of either 

 mind or body ; and Hume has expressly written an essay to 

 prove the insufficiency of climate with respect to the varieties 

 of national character. Now the intensity of light unquestionably 

 affects the colour of the surface, although not to the degree of 

 Ethiopian blackness ; heat the texture and growth of the hair ; 

 and quantity of nourishment the size. But the effects of these 

 circumstances are superficial, even on animals necessarily less 

 protected against their influence than man. The skulls of 

 foxes belonging to northern regions are not different from 

 those of France or Egypt : the tusks of the elephant, and 

 the horns of the stag and rein deer, may acquire a larger 

 size when the food is more favourable to the production 

 of ivory or horn, but the number and articulations of the 



Infirmary of Edinburgh. 138.), one mentioned by the Due de Rochefoucault 

 Linncourt, (Travels through the United States. Vol. iii. p. 263.). A Sussex 

 girl was, a few j'cars ago, a patient in St. Thomas's Hospital, whose family 

 were all white, but whose left shoulder, arm, and hand, were of a negro black- 

 ness, except that a stripe of white ran between the elbow and arm-pit. 

 (Dr. Wclls's Works.} A white woman in twenty years became as black as a 

 negress, without any evident reason, according to a statement in the London 

 Medical and Physical Journal. (1811. p. 24.); and other such cases may 

 perhaps be discovered, though those which I have read appear to have been 

 instances of cutaneous disease. 



* An example lias already been mentioned (563* B.) of what is a still stronger 

 argument, the .tiiniiffniirnim production of two individuals of dinerent varieties, 

 of a negro and a Caucasian, by the same mother. 



