1 98 SCIENCE PROGRESS 



causes the absence of pigment from the lower sides of flat-fishes, 

 but this character is neither useful nor adaptive. The real 

 distinction between the two kinds of characters, according to 

 my views, is that those of one kind are due to external 

 stimulation, those of the other kind are independent of external 

 causes ; the latter are mutations, the former may be called 

 modifications. 



Huxley's classification of the races of mankind is a some- 

 what simple one. He divides them into two primary divisions, 

 resembling perhaps genera, namely the Ulotrichi with woolly 

 hair, and the Leiotrichi with straight hair. The Leiotrichi he 

 subdivides into four groups : the Australoid, the Mongoloid, 

 the Xanthochroic or fair whites, and the Melanochroi or dark 

 whites. The characters in which the races differ are colour of 

 skin, hair, and eyes, shape of cranium, whether brachycephalic 

 or dolichocephalic, character of hair, projection of jaws, shape 

 of features, especially nose and eye-apertures. 



The negro race is one of the most distinctly marked : its 

 characters being black-brown skin, woolly hair, prognathous, 

 brachycephalic skull, thick out-turned lips, flat nose. The type 

 is most perfectly developed in equatorial Africa as in Guinea ; 

 to the north it has crossed with the Berbers, on the east with 

 the Arabs ; to the south it shows reduced characters apparently 

 without crossing. The Bushmen and Hottentots, while ap- 

 parently belonging to the negro stock, are much lighter in 

 colour, and this is some evidence that the black of the negro 

 is originally due to the tropical sun. In the East Indian 

 Archipelago is a type allied to the negro, but not identical, 

 extending through the region called from its presence Melanesia, 

 from Papua to Fiji. These have woolly hair, but the brow 

 ridges and the nose are more prominent than in the negro ; 

 the colour varies from black to chocolate. The Tasmanians, now 

 extinct, are stated to have been an isolated colony of this race. 

 The Andaman islanders form a connecting link between the 

 eastern blacks and the negroes, but although they have frizzled 

 hair, which they shave off, they are brachycephalic, less pro- 

 gnathous than the negro, and the nose is narrower. The 

 Australians are brown in colour with wavy black hair, 

 dolichocephalic, having prognathous skulls with well-developed 

 brows, and wide but not flat noses. Allied types are believed 

 to occur in India, namely the hill-tribes, descended from the 



