Descent of Man, and Selection in Relation to Sex, v.1

Page 130

2!4 THE DESCENT OF MAN. PART I. to the latitude of the country whence they had come. 'Vith the negro the immunity, as far as it is the result of acclimatisation, implies exposure during a prodigious length of time ; for the aborigines of tropical America, who hare resided there from time immemorial, are not exempt from yellow-fever; and the Rev. B. Tristram states, that there are districts in Northern Africa which the native inhabitants are compelled annually to leave, though the negroes can remain with safety. That the immunity of the negro is in any degree correlated with the colour of his skin is a mere conjec­ture: it may be correlated with some difference in his blood, nervous system, or other tissues. Nevertheless, from the facts above alluded to, aud from some connec­tion apparently existing between complexion and a tendency to consumption, the conjecture seemed to me not improbable. Consequently I endeavoured, with but little success,48 to ascertain how far it held good. The 4S In the spring of 1862 I obtained permission from the Director­General of the Medical department of the Army, to transmit to the surgeons of the various regiments on foreign service a blank table, with the following appended remarks, but I have received no returns. "As several well-marked casct-l have been recorded with our domestic " animals of a relation between the colour of the dermal appendages " and the constitution ; and it being notorious that there is some limited " degree of relation between the colour of the races of man and the " climate inhabited by them ; the following investigation seems worth "consideration. Namely, whether there is any relation in Europeans " between the colour of their hair, and their liability to the diseases of "tropical countries. If the surgeons of the several regiments, when " stationed in unhealthy tropical districts, would be so goou as first to "count, as a ~tandard of comparison, how many men, in the force " whence the sJCk are drawn, have dark and light-coloured hair and "hair of intermediate or doubtful tints ; and if a similar account ~ere " k ept by the same medical gentlemen, of all the men who suffered ::from malarious and yellow fevers, or from dysentery, it would soon be apparent, after some thousand cases had been tabulated, whether "there exists any relation between the colour of tho hair and consti­" tutional liability to tropical diseases. Perhaps no such relation would CJJAP. VII. THE RACES OF MAN, 245 late Dr. Daniell, who had long lived on the West Coast of Africa, told me that he did not believe in any such relation. He was himself unusually fair, and had with­stood the climate in a wonderful manner. 'When he first arrived as a boy on the coast, an old and expe­rienced negro chief predicted from his appearance that this would prove the case. Dr. Nicholson, of Antigua, after having attended to this subject, wrote to me that he did not think that dark-coloured Europeans escaped the yellow-fever better than those that were light­coloured. Mr. J. 1\'I. Harris altogether denies 49 that Europeans with dark hair withstand a hot climate better than other men; on the contrary, experience has taught him in making a selection of men for service on the coast of Africa, to choose those with red hair. As far, therefore, as these slight indications serve, there seems no foundation for the hypothesis, which has been aecepted by several writers, that the colour of the black races may have resulted from darker and darker indi­viduals having survived in greater numbers, during their exposure to the fever-generating miasmas of their native countries. Although with our present knowledge we cannot account for the strongly-marked differences in colour between the races of man, either through correlation with constitutional peculiarities, or through the direct action of climate; yet we must not quite ignore the " be discovered, but the investigation is well worth making. In case ·'any positive result were obtained, it might be of some practical use " in selecting men for any particular service. Theoretically the result " would be of high interest, as indicating one means by which a race "of men inhabiting from a remote period an unhealthy tropical climate, "might have become dark-coloured by the better preservation of dark­" haired ~r dark-complexioned individuals during a long succession of " ::;eneratwns." 4g 'Anthropological Review,' Jan. ISGG, p. xxi.