112 THE MECHANICAL FUNCTIONS. 



ticular formation is the result of a combination 

 of the same elementary structures. Of these 

 elements the most important, and that which 

 generally composes the chief bulk of the skin, 

 is the Cerium, or true skin. The outermost layer 

 is termed the Epidermis, Cuticle, or scarf -skin; 

 and between these there is often found an inter- 

 mediate layer denominated the Rete Mucosum, 

 or the Pigmentum. 



The corium is generally of considerable thick- 

 ness, and is composed of strong and tough fibres, 

 closely compacted together, and pervaded by 

 innumerable ramifications of blood-vessels of 

 every kind. It is endowed with great flexibility, 

 and is capable of being considerably extended ; 

 properties which fit it for readily accommodating 

 itself to all the movements of the body and 

 limbs, and to the variable bulk of the parts it 

 covers. Being also very elastic, it soon regains 

 its natural form and dimensions when left to 

 itself after being stretched. The skin is con- 

 nected with the subjacent muscles and other 

 parts by a large quantity of cellular texture, 

 which, according to the particular intentions of 

 its formation, sometimes binds it tightly over 

 these parts, and on other occasions allows of a 

 free and extensive motion. This latter property 

 is remarkably exemplified in the Racoon, an 

 animal in which the skin hangs loosely on the 

 limbs, and encloses the body like a wide elastic 



