THE INTEGUMENT. 67 



against tlie absorption of poisons, so that these, as is familiar 

 to every one, may be handled with impunity when the cuticle 

 is perfect, and yet may be introduced into the system by a 

 very small wound. The surface of the body is not, however, 

 to be supposed incapable altogether of absorbing substances 

 from without. Fluids left in contact with the cuticle, and 

 even solid substances rubbed into it, are gradually absorbed. 

 Probably such absorption takes place principally in the orifices 

 of the sweat glands, but even these are lined with thin pro- 

 longations of the horny cuticle, which therefore cannot be 

 regarded as totally impermeable. 



A variable amount of pigment exists in the deep cells of 

 the cuticle, and it is on this that all duskiness of skin 

 depends, the greatest amount of pigment being in the cuticle 

 of the negro. Among the chemical changes, however, which 

 take place in the epidermal cells as they approach the sur- 

 face, is the disappearance of the pigment; and the horny 

 layer is pale which is raised by a blister from the negro's 

 skin. The red tints of the skin are not dependent on pig- 

 ment, but 011 the blood shining through from the blood- 

 vessels in the cutis vera. 



42. The cutis vera, derma, corium, or true skin, has a white 

 fibrous basis. Its surface is thrown into papillae or finger- like 

 prominences, the largest of which are about j^- of an inch 

 in length. In the papillary part, it is impossible to detect 

 separate fibres ; while in the deeper part, the white fibrous 

 substance is arranged in interlacing bands, the spaces between 

 which get larger as the subcutaneous tissue is approached, 

 into which the skin gradually blends. In the deep part also, 

 elastic fibres curl and twine in all directions, and there is a 

 copious network of connective-tissue-corpuscles with long 

 processes. The superficial part is much more vascular than 

 the deep ; for close to the surface of the cutis is spread one 

 of the richest networks of capillary blood-vessels in the body, 

 with a loop of blood-vessel in every papilla. It is from these 

 blood-vessels that the epidermis receives its nourishment. 

 The epidermis is moulded to the papillary surface of the 

 cutis ; and in the hands and soles of the feet, which have the 

 papillae disposed in thickest rows, the trace of this arrange- 

 ment is left oil the surface of the cuticle, in the form of the 



