MYOLOGY 157 



regions — the great serratus in the thoracic, and the levator 

 anguh scapulae in the cervical — we prefer to study them 

 separately. 



We remember that in man this muscle arises from the 

 transverse processes of the upper cervical vertebrae and is 

 inserted into the superior portion of the spinal border of the 

 scapula, into the portion of this border which is situated 

 above the spine; it also contributes to the formation of the 

 floor of the supraclavicular region. 



When it contracts, it draws the superior portion of the 

 scapula forwards and upwards, and causes a see-saw move- 

 ment, for at the same time the inferior angle of the scapula 

 is directed backwards. Taking its fixed point at the 

 shoulder, it directly extends the neck if the muscle of one 

 side acts at the same time as that of the opposite ; but 

 if only one muscle contracts it inclines the neck to the cor- 

 responding side. 



It is to be noticed that during movements a little more 

 active than the ordinary the levator anguli scapulae, as 

 moreover the other miuscles of the neck do, becomes very 

 distinct. W^e have, indeed, often remarked that, apart from 

 these movements, each time the support of one of the fore- 

 limbs is brought into requisition a brusque contraction of the 

 muscles of this region accompanies it. 



This contraction gives the impression that, as on the one 

 hand, each support determines a momentary arrest of 

 progression, a jolt, and on the other hand, the head con- 

 tinues to be projected in the forward direction, the latter 

 should be retained. But it cannot be so except by an effort 

 in the opposite direction — that is to say, by the brusque 

 contraction which we have just pointed out. 



Analogous contractions also take place in a man while 

 running at the beginning of each contact of the lower limbs 

 with the ground. 



We may add, apropos of this latter, that displacements 

 of the head, sometimes in very pronounced fashion, take 

 place during simple walking, and that every time one of 

 the lower limbs is carried forwards the head is projected 

 in the same direction. These displacements, which we 



