The existence of this vascular net-work is placed beyond a doubt by fine injections which change the colour of the skin entirely externally, without altering it much within. This is, as I have observed, the principal seat of the numerous eruptions most of which are really foreign to the cutaneous chorion. We may then consider the reticular body as a general capillary system, surrounding the cutaneous organ, and forming with the papillæ a layer between the chorion and the epidermis. This system contains in most men, only white fluids. In negroes, these fluids are black. They have an intermediate tinge in the tawny nations. We know how much the shades vary in the human race. Hence the colouring of the skin resembles nearly that of the hairs, which evidently depends upon the substance existing in their capillary tubes; it is analogous to that of the marks at birth, that are commonly called nævi materni, and in which we never see a layer of fluids extravasated between the epidermis and the chorion. Moreover, I think we know but little as yet concerning this substance, which fills a part of the external capillary system. It does not circulate in it, but appears to remain there till another replaces it. When we examine the skin of a negro, we see a black teint, and that is all. In maceration I have observed that this teint is sometimes removed with the epidermis, and that it sometimes remains adhering to the chorion. It is very evidently foreign to both, since both have the same colour in whites as in blacks. It is never reproduced, after it has been removed; for cicatrices are white in all people. Is there in white people a white substance which, remaining in the external capillary system, corresponds to that of negroes, or does the colour of their skin depend only upon the epidermis and chorion? I have been tempted to believe that they also have a colouring substance, since the long-continued action of a powerful sun evidently blackens them. This circumstance has even made me believe that whiteness is natural to all men, and that there was but one primitive race which has degenerated according to different climates.