84 MUTUAL RELATIONS OF THE HUMAN FAMILY. 



lour of the skin exists in the epidermis only ; and it depends upon the ad- 

 mixture of certain peculiar cells, termed pigment-cells, with the ordinary 

 epidermic cells. These pigment-cells, as will be shown hereafter ( 163), are 

 distinguished by their power of generating or secreting colouring-matter of 

 various hues ; and all the varied shades of colour, presented by the different 

 races of men, are due to the relative amount of these cells, and to the parti- 

 cular tint of the pigment which they form. It would be easy, by selecting 

 well-marked specimens of each race, to make it appear that colour affords 

 sufficient distinctive marks for their separation: thus, for example, the fair 

 and ruddy Saxon, the jet-black Negro, the olive Mongolian, and the copper- 

 coloured North American, would seem positively separated frdm each other 

 by this character, propagated, as it seems to be, with little or no perceptible 

 change, from generation to generation. But although such might appear to 

 be the clear and obvious result of a comparison of this kind, yet a more pro- 

 found and comprehensive survey tends to break down the barrier that would 

 be thus established. For, on tracing this character through the entire family 

 of Man, we find the isolated specimens just noticed to be connected by such 

 a series of links, and the transition from one to the other to be so very gradual 

 that it is impossible to say where the line is to be drawn. There is nothing 

 here, then, which at all approaches to the fixed and definite marks, which have 

 been noticed as serving though equally trivial in themselves to establish 

 specific distinctions among other tribes of animals. 



80. But further, there is abundant evidence that these distinctions are far 

 from being constantly maintained, even in any one race. For among all the 

 principal subdivisions, alblnoism, or the absence of pigment-cells, occasion- 

 ally presents itself; so that the fair skin of the European may present itself 

 in the offspring of the Negro or of the Red Man. On the other hand, in- 

 stances are by no means rare, of the unusual development of pigment-cells 

 in individuals of the fair-skinned races ; so that parts of the body are of a 

 dark red or brown hue, or are even quite black. Such modifications may 

 seem of little importance to the argument; since they are confined to indi- 

 viduals, and may be put aside as accidental. But there is ample evidence, 

 that analogous changes may take place in the course of time, which tend to 

 produce a great variety of shades of colour, in the descendants of any one 

 stock. Thus, in the great Indo-Atlantic family, which may be unquestion- 

 ably regarded as having had a common origin, we find races with fair com- 

 plexion, yellow hair, and blue eyes, others presenting the xanthous or olive 

 hue, and others decidedly black. A similar diversity may be seen among 

 the American races, which are equally referrible to one common stock ; and 

 it exists to nearly the same extent among the African nations, which are simi- 

 larly related to each other. It may be freely admitted that, among European 

 colonists settled in hot climates, such changes do not present themselves within 

 a few generations ; but in many well-known instances of earlier colonization 

 they are very clearly manifested. Thus the wide dispersion of the Jewish 

 nation, and their remarkable isolation (maintained by their religious observ- 

 ances) from the people among whom they live, render them peculiarly appro- 

 priate subjects for such observations; and we accordingly find, that the bru- 

 nette complexion and dark hair, which are usually regarded as characteristic 

 of the race, are frequently superseded, in the Jews of Northern Europe, by 

 red or brown hair and fair complexion ; whilst the Jews who settled in India 

 some centuries ago, have become as dark as the Hindoos around them. 



81. The relation of the complexions of the different races of Men to the 

 climates they respectively inhabit, is clearly established by an extended com- 

 parative survey of both. From such a survey the conclusion is inevitable, 

 that the intertropical region of the earth is the principal seat of the black races 



