processes of albinism and melanisnz occur as patholog ical conditions in all races, and may materially influence the general hue of a community. Among the Pueblo Indians of Arizona it is not at all uncommon to observe fair skins and blue eyes, and this in families of pure blood. It is explained by the prevalence of albinos among them, whose traits are transmitted by descent. Either partial or complete albinism is frequent in the Negro race. The skin becomes of a dead white, usually retaining small patches of the normal black color, thus presenting a mottled appearance. The tendency is said to be hereditary.
of melanism, or turning dark, are frequent in the white race. The areola of the nipple in pregnancy generally changes to a decided brown ; freckles and moles are other local instances ; certain skin diseases present the same phenomenon, as also a variety of cancer ; while the degeneration of the suprarenal capsules —organs in no way connected, so far as known, with the functions of the skin—is associated with a bronzing of the entire surface of the body.
These facts show that color is influenced by obscure physiological changes quite irrespective of climate. There seems reason to believe that this has taken place on an extensive scale within the historic period. The Roman historians describe the Britons as a blond race with yellow hair ; but their descendants, as represented in the inhabitants of Wales and Cornwall, have dark complexions and brown or black hair. The Cherokees of East Tennessee and Northern Georgia are described by the early travellers as unusually fair, some of them as much so as South ern Europeans. At present they are not noticeably fairer than other tribes. Change of food and manner of living may explain these anomalies.
Taken together, colors serve as an excellent rough-and-ready means of classifying mankind, well marked in their extremes, but in the mean blending so constantly one into another that no hard and fast lines can be laid down, and surely misleading the ethnologist who would depend on these alone as a basis for a system.
Odor of the connected with the color of the skin, and probably dependent upon it, is the odor which it exhales. This is per ceptible in health in direct proportion to the amount of carbonaceous matter secreted from the blood. Brunettes emit more positive odors than
blondes, the Semitic than the Aryan nations, and the full-blood Negroes most of all. Their acrid, ammoniacal effluvium is said to have been per ceived many miles at sea, and in the days of the slave-trade often betrayed the living cargo to the British cruisers.
Even the most cleanly white person is instantly recognized through the sense of smell by his dog, and the lower races of men with highly developed olfactory powers perceive the odor of the European as distinct ly as we do that of the Negro. In the dialect of the Chilian half-breeds there is an adjective, catinca, to express this smell of a white man. Were our olfactory nerves as sensitive as those of many animals—as the deer's, for instance, which will scent the hunter a mile away—this would prob ably be the most positive race-distinction of all ; but, as it is, we can treat of it only as an accessory to the color of the skin.
Parasites of the the physiological constitution of the skin depends another classification of the human race which was suggested by Darwin. Indeed, he advanced it as an evidence of the specific diversity of the species. This is the difference in the species of parasites that make their home upon or within the human body. It is a familiar fact to naturalists that the lice and fleas which infest different species of animals are themselves specifically diverse ; and this holds good of some internal parasites of the same generic character. According to the testimony of several investigators, the pediculi which harbor in the hair and skin of the negro are of 'different species from those on whites, and neither will continue on persons of the other race. The observations, however, on this subject are too scanty to admit of any positive generalizations. Habits and locality have probably more to do with the facts quoted than diversity of race. In communities, as the large cities of the United States, where the white and black races are thrown together under pre cisely similar conditions, no such difference of parasitic life has been noticed. On the contrary, school-teachers are often made aware of the facility with which the unkempt children of either race will transfer pediculi to the other.