402 TEGUMENTAL SYSTEM. 



runnino- from the interior of the cavity of the cranium to abut 

 against the vestibule and cochlea, for the conduct of the seventh 

 pair of nerves. At its termination it is closed by a cribriform 

 osseous plate, which is not flat, but bulges a little, through 

 whose perforations are transmitted the fasciculi of the portio 

 mollis. The principal part of this plate is set opposite to the 

 cochlea, but a portion extends across to the vestibule ; so that 

 nervous filaments gain admission into both cavities. 



Section XI. 

 TEGUMENTAL* SYSTEM. 



COMPRISING THE SKIN, HAIR, CELLULAR MEMBRAN 

 AND FAT. 



OF THE SKIN. 



THE ancient anatomists placed the skin, cellular membrane, 

 and panniculus carnosus, in the same class or set of parts, de- 

 nominating them the common integuments; the epithet "com- 

 mon" merely serving to denote their presence and uniformity 

 over the body generally. And indeed, at the present day, the 

 appellation of " common integuments" is still in use ; though 

 its meaning is now hmited to the skin alone. 



Co7nposition. — ^The skin is composed of three parts, differing in 

 appearance, texture, and organization from each other : viz. the 

 cutis, cuticle, and rete mucosum. 



Cutis. 



The cutis or dermis, sometimes designated the cutis vera or 

 true skin, from its being the most substantial of the constituents 

 of the skin, is that part which the tanner converts into leather: 

 it lies underneath, and may be said to be (in the full sense of the 

 word) the support of the other two. 



Attachment. — The cutis is attached to the subjacent parts by 

 cellular membrane, in some places so tensely that little or no 

 motion is admitted of; in others so loosely that it admits of being 

 thrown into folds : about the forehead, upon the back, around 



* I was for some time at a loss for an appropriate title for this system of 

 parts. The one I have adopted (synonymous with the epithets " investing'," 

 " enveloping," " covering") is the most expressive — of any one I could 

 select — of the general physiological character of the contained parts. 



