MOVEMENTS OF THE HEAD. 183 



or the expression." And again: "A countenance 

 may be distinguished by being expressive of 

 thought; that is, it may indicate the possession 

 of the intellectual power. It is manly, it is 

 human; and yet not a motion is seen to show 

 what feeling or sentiment prevails." 



Here Bell uses the term " expression " as confined 

 to mobile, nerve-muscular, or kinetic modes of 

 expression, and carefully distinguishes between 

 them and the conditions of development which 

 indicate the coincident condition of development 

 of the brain. The permanent forms of the head 

 and face as indicative of the states of the mechanism 

 of the mind have been often described in treatises 

 on physiognomy. Much expression may be seen 

 in the various movements and postures of the head, 

 as well as in its size, form, and proportions. The 

 movements of the head or skull are, no doubt, 

 largely due to movements of the neck, which is 

 made up of the seven cervical vertebrae. The 

 skull can be rotated on the neck ; it can be flexed 

 and extended on the first vertebra, which is called 

 the atlas. To simplify description we shall here 

 speak only of movements of the head with regard 

 to the body at large, neglecting the question as to 

 how far the vertebrae of the neck may take part in 

 such movements. 



For descriptive purposes we may conveniently 

 speak of two axes of the head : (1) the interparietal, 

 or transverse axis, passing from one ear across to the 

 other ; (2) the front o-occipital or antero-posterior 

 axis, passing from the centre of the forehead to the 



