"It cannot be doubted that the development of the pigment-cells of the skin is very much influenced by the action of light; and in this respect there is a remarkable correspondence between animals and plants-the coloration of the latter, as is well known, being entirely due to that agent. Thus, it is a matter of familiar experience, that the influence of light upon the skin of many individuals, causes it to become spotted with brown freckles; these freckles being aggregations of brown pigment-cells, which either owe their development to the stimulus of light, or are enabled by its agency to perform a decided chemical transformation which they could not otherwise effect. In like manner the swarthy hue, which many Europeans acquire beneath exposure to tropical climates, is due to the development of many dark pigment-cells, and to this we usually find the greatest disposition in inviduals or races that are already of somewhat dark complexion. The deep blackness of the Negro skin seems dependent upon nothing else than a similar cause, operating through successive generations. It is well known that the new-born infants of the Negro and other dark races, do not exhibit nearly the same depth of color in their skins, as that which they present after the lapse of a few days, when light has had time to exert influence upon their surface, and further, that in those individuals who keep themselves during life most secluded from its influence, we observe the lightest hue of the epidermis. Thus among the intropical nations, the families of chiefs, which are not exposed to the sun in the same degree with the common people, almost always present a lighter hue; and in some of the islands of the Polynesian Archipelago, bordering on the equator, they are not darker than the inhabitants of southern Europe.'

Thus much from Carpenter. The quotation made from him throws some "light" on our subject. What men have long contended for, it fully proves, viz.: that a change of climate has much to do with the color of the skin; that the action of light, by some means, developes

has its influence in giving a deeper tinge to the skin. It is supposed that the calorific rays of the sun stimulate that gland to greater action. If that gland, why not the other glands of the human organism? For, if I mistake not, the function of all of them is nearly the same.

the pigment that makes the African black, the Mongolian olive-hued, the North American savage copper-colored.* Our color is confined to the surface merely, and, therefore, the argument against the specific unity of the race, on the ground of hue, as Dr. Good remarks, is only "skin deep."

Hair and nails, as well as the hoofs and horns of animals, are developed like the epidermis, from the subjacent membrane, and therefore the same causes that affect the skin would affect the color of the hair. The texture of the hair is everywhere the same. It may be straight like the Indian's, or wooly like the Negro's, but microscopic examination clearly demonstrates that the common notion, that the substance which grows on the head of dark-colored tribes is wool, is altogether a mistake. It bears no resemblance to wool, save in its crispiness and tendency to curl.

If phrenology be true, (although against some of its teachings there are powerful arguments), mental culture has much to do with the formation of the skull; and even the pelvis, limbs, abdomen and thorax, vary with corresponding degrees of civilization. Long ages of starvation, nakedness, ignorance and abuse, tend powerfully to reduce the physical man, in almost every respect. Under these influences, the limbs become lank and irregular; the belly projects; the forehead retreats; the nose flattens; the teeth and cheek bones become prominent, and mental and moral degradation correspond. The story of the Australians proves this; or, more to the point, the miserable Bushmen in South Africa. The latter wander in forests; sleep in dens and caves of the earth; eat snakes, lizards, roots; take no pains to wash or cook their food; and their language is a "gutteral grunt." Originally they were a decent kind of people; now they are not considered worth enslaving even. But place these Bushmen under the influences of civilization, give them wholesome nutriment and mental and moral culture for a few generations, and the general form of the body would change.

4 The tree-frog, kept in the shade, becomes a light yellow; exposed to the sun, he turns to a dark green. The nercis lucustris, (I do not know the common name), is whitish in the shade, but turns red on being exposed to the sun.

On this subject I will make two more quotations from Prof. Carpenter :

"The analogical argument derived from the phenomena presented by the domesticated species among the lower animals, is decidely in favor of the specific unity of the human race; the differences which have sprung up, in course of time, amongst the inhabitants of different parts of the world, being such as we have a fair right to attribute, according to the recognized principles of zoology, to the modifying influence of external conditions, acting upon a constitution peculiarly disposed to yield to it." (p. 76.)

That is, domesticated animals, known to have had a common ancestry, vary as extremely as the human race. This is true of dogs especially. And the differences which present themselves among these domesticated animals, are of the same kind as those that present themselves among the different races of men. They vary, too, with climate and country. The blood-hound in Spain was one thing, but introduced into the West Indies, in about three hundred years it degenerated into a wild race of a different form. The hog, in the same country, in a domesticated state, had various colors; but brought to our western shores, and left to run wild, it becomes uniform in color, its head elongated, and its bristles gave place to an apparent (or real) species of fur. As great changes have taken place in the horse, ass, ox, sheep, goat, dogs, birds, &c., carried to South America and the West Indies, three and a half centuries ago, by the Spaniards.

Pass, if you please, from the lower types of animal organization, over into the vegetable kingdom. Vegetables change with the climate. Naturalists inform us that apples, pears, plums, variable as they are in taste, form and color, sprang from the same seedling originally; and that the same is true of the cow-slip, ox-slip, primrose and polyanthus. Go into the granary of the husbandman, and look among his Indian corn. The most of it may be yellow or white. But occasionally you will find a red ear, a blue ear, a black ear, &c. The shape of the kernels, too, differs as much as the skulls of men belonging to different races. The facial angle, that is if we measure according to the method of Camper, varies in

man but ten degrees,-70° in the Negro, 80° in the European, and in no respect does the shape of the head vary more. Is there not a vastly wider difference between a kernel of rice-corn, for example, and the form of an old fashioned kernel of yellow corn? And if all our variously colored and shaped maize, sprang from one primal seedling, does not analogy teach, that the variously colored and shaped men that go to make up the five races, might have sprung from one original pair? And was St. Paul out of the way in affirming before the Athenians that we are all of one blood?

Prof. Carpenter says: "The most important physiological test of specific unity or diversity, is derived from the phenomena attending the reproductive process. It is well known that in plants, the stigma of the flower of one species may be fertilized with the pollen of an allied species; and that from the seeds produced, plants of an intermediate character may be raised. These hybrid plants, however, will not perpetuate the new race; for, although they may ripen their seed for one or two generations, they will not continue to produce themselves beyond a third or fourth. But if the intervention of one of the parent species be employed-its stigma being fertilized by the pollen of the hybrid, or vice versa-a mixed race may be kept up some time longer, but it will then have a manifest tendency to return to the form of the parent whose intervention has been employed. Where, on the other hand, the parents themselves were only varieties, the hybrid forms are but another variety, and its powers of reproduction are rather increased than diminished; so that it may continue to propagate its own race ad infinitum. In this way, many beautiful new varieties of garden flowers have been obtained; especially among such species as have a natural tendency to change their aspect. Amongst animals, the limits of hybridity are much more

5 In the adult Campanzee 35°; in the Orang 30°; for though as high as 60° in some new-born apes, the jaws are made to project wonderfully at the time of second dentition. These higher monkey tribes differ from man in other important particulars. They have three less vertebræ than a human being; they have a peculiar pouch connected with the larynx that belongs not to the human species, also less perfect feet. These dissimularities are not found among the varieties of men; we meet with them only by stepping down among a lower species.

narrow, since the hybrid is totally unable to continue its race with one of its own kind; and although it may be fertile with one of its parent species, the progeny will, of course approach in character to the pure breed, and the race will ultimately merge into it. On the other hand, in animals as among plants, the mixed offsprings originating from different races within the limits of the same species, generally exceed in vigor, and in the tendency to multiply, the parent races from which they are produced, so as to gain ground upon the older varieties, and gradually to supercede them. In this manner, by the crossing of the breeds of our domesticated animals, many new and superior varieties have been produced. The general principle is, then, that beings of distinct species, or descendants from stocks originally different, cannot produce a mixed race which shall posses the capability of perpetuating itself; whilst the union of varieties has a tendency to produce a race superior in energy and fertility to its parents.

"The application of this principle (if it be admitted as such) to the human races leaves no doubt with respect to their specific unity; for, it is well known, not only do all the races of men breed freely with each other, but the - mixed race is generally superior in physical development, and in tendency to rapid multiplication, to either of the parent stocks; so that there is much reason to believe that, in many countries, the mixed race between the Aborigines and European colonizers will untimately become the dominant power in the community. This is specially the case in India and South America." (p. 77.)

Such is the test, furnished by Carpenter, derived from the phenomena of the reproductive process. And he has given us one of a psychological character equally as conclusive, though I have not space to quote it.

I regret the attempts of scientific men to unsettle our faith in the doctrine of the unity of the race. So far as

6 When located at Richmond, Va., the writer heard this doctrine boldly denied. It was there contended that the mulatto, or the offspring of a European father and Indian mother, (or vice versa), could not perpetuate his species, with his own kind, beyond the fifth or seventh generation. I have more faith, however, in the affirmation of Carpenter, than in the opinions of uneducated men, who are anxious to justify slavery.