ANATOMY OF THE HEAD. 175 



which penetrate it to cuter the skin. A very large nervous 

 bundle enters it from under the shoulder, and it receives 

 one or more twigs from between each rib : it is likewise as 

 well supplied with bloodvessels fi'om the intercostals and 

 neighbouring parts. Therefore its general living powers 

 are very considerable ; and these are further aided by the 

 length of its muscular fibre, which enables it to act instan- 

 taneously, and with irresistible effect. A horse, by the 

 spasmodic power of this muscle alone, can sometimes shake 

 off the harness, which the ingenuity of man has been 

 exerted to fix upon him. 



ANATOMY OF THE HEAD. OF THE HEAD GENERALLY. 



DESCRIPTION OF PLATE VI. 



THE RIGHT DIVISION OF THE HEAD A LITTLE TO THE LEFT OF 

 THE MEDIAN LINE. 



a. The septum nasi, or cartilaginous wall which sepa- 

 rates the nostrils. The Schneiderian membrane is still 

 upon the cartilage, consequently the ramification of the 

 vessels are faithfully delineated ; &, the cerebrum ; c, the 

 cerebellum ; d, the frontal and facial sinuses ; e, the tongue ; 

 /, the soft palate, showing its pendulous condition as well 

 as its inclination backwards ; g, the fauces. The lines 

 crossing this part denote the courses taken by the food and 

 air as they enter the stomach or lungs to nourish the 

 body ; showing, likewise, that these cross each other ; h, 

 the bag of the pharynx ; A, the opening of the nostrils ; 

 i, the epiglottis ; j, the larynx ; /c, the oesophagus or gullet ; 

 /, the trachea ; m, the spinal marrow, covered by the arach- 

 noid : part of the dura mater or outer covering of the 

 spinal cord may be seen immediately above, in a line which 

 weaves anteriorly ; n, the spinal marrowy in its passage 

 through the foramen magnum, divested of its coverings ; 

 0, the tooth-like process, whence the second cervical ver- 

 tebrtc is called the dentata ; p, the cup of the atlas, into 

 which the process of the dentata fits. 



