378 MUSCLES. 



tween it and its fellow, and reaching from the base of the os 

 hyoides to the chin. This muscle is concealed by the anterior 

 belly of the digastricus. When it contracts, it draws the os 

 hyoides upwards and projects the tongue.* 



The Genio-Hyoideus, 



Is concealed by the last; by turning over the anterior edge of 

 which, it is seen. It arises tendinous from the tubercle on the 

 posterior side of the symphysis of the lower jaw; and, in- 

 creasing somewhat in breadth, is inserted into the anterior part 

 of the base of the os hyoides. 



It draws the os hyoides upwards and forwards.! 



(For the muscles of the tongue, see Mouth.) 



There are seven pairs of muscles, on the front and sides of 

 the cervical vertebrae, which lie closely upon them. They are 

 named from their situations and shapes. 



1. Longus Colli. 



The Longus Colli is next to the middle line of the vertebrae. 

 It arises from the sides of the bodies of the three superior ver- 

 tebrae of the back, and from the anterior edges of the trans- 

 verse processes of the five lower cervical vertebrae. Its fibres 

 pass somewhat obliquely upwards and inwards, to be inserted 

 into the front of the bodies of all the cervical vertebras. 



It bends the neck forwards, and to one side.J 



* Varieties. Sometimes a part of it is inserted into the middle tendon of the 

 digastricus, or is joined with the sterno-hyoidcus. 



t Varieties. Sometimes a distinct fasciculus of this muscle is inserted into 

 the greater part of the cornu of the os hyoides. Sometimes the-re is but one 

 muscle. Rarely it is double on both sides. 



t Varieties. Sometimes a fasciculus from the first or second rib, or from the 

 body of the sixth or seventh vertebra of the neck, joins it. 



