RETE MUCOSUAl, 175 



Emily. Do you really mean that the colour of the 

 skin is the same in all mankind ? If such is the case, 

 why then I have always been in an error respecting the 

 seat oi colour. Does not the poet speak of a fellow-being 

 having a " skin not coloured like my own" ? 



Dr. B. Yes but neither poets, nor any other per- 

 sons are bound, in the iamiliar use of words, to adhere 

 to their strict anatomical meaning. The seat of colour 

 is not in the true skin, but in another part which we 

 shall describe presently. 



The external layer of the integuments, or epidermis, 

 as it is called which is very well seen when raised by 

 a blister is formed by minute scales lapping over each 

 other, as in the skin of a fish. From their extreme 

 minuteness, this structure is visible only under a power- 

 ful microscope. It is said to be furnished with neither 

 blood-vessels, absorbents, nor nerves, and its only use 

 seems to be to afford protection to the more delicate' 

 parts beneath. Its colour is nearly alike in the fair as 

 well as dark coloured races, but it is generally a little 

 deepened by exposure to the rays of the sun. 



Between these two layers, we find one still more del- 

 icate, called the rete mucosum. Its nature is very im- 

 perfectly known ; it is not decided whether it be an 

 extremely fine net-work of capillary vessels, filled with 

 variously colored fluids, or merely an unorganised pulp* 

 This layer has never yet been discovered in the white 

 races, though there can be little doubt that it does exist, 

 and that it is in consequence of its extreme delicacy 

 alone, that it has eluded observation, 



Emily. Why should it be so much more easily dis- 

 covered in the Negro, than in white people ? 



Dr. B. Because, in the former it is of a black color ? 

 and is perhaps thicker, though it is so extremely thin 

 and delicate that no small nicety of dissection is requi- 

 site, in order to find it. When removed and placed in 

 water, it diffuses itself ia the fluid, and gives a turbid 



