20 PHYSIOLOGY AT THE FAKM. 



But those muscular fibres which enter the tongue from adja- 

 cent points have a much greater power over its motions. The 

 hyoid bone is termed the bone of the tongue. This name is 

 hardly correct ; nevertheless it is a principal point whence 

 muscular fibres proceed into the tongue. The hyoid bone 

 resembles the upsilon or v of the Greeks ; by modern veter- 

 inary writers it is likened to a spur. Its convex part presents 

 between the larynx and the anterior-inferior point of the lower 

 jaw its branches proceed backwards in connection with the 

 upper margin of the larynx. These branches constitute the 

 concavity of the spur ; while from the middle of its convexity, 

 pointing forwards there is a straight projection (called appendix 

 by some) corresponding to the neck of the spur. The part 

 resembling the spur is small compared to the lesser and greater 

 horns. The lesser horns articulate with the body, and have an 

 upward, forward, and outward direction : the greater horns are 

 long and flat, passing from below backwards and upwards ; 

 their inferior extremities articulate each with one of the lesser 

 horns. These few particulars show very considerable differ- 

 ences between the hyoid in man and that bone in the horse. 



The hyoid bone is connected by muscular fibres not only 

 with the tongue, but also with the lower jaw, the temporal bone, 

 the larynx, the pharynx, and the breast-bone. When these 

 muscular fibres contract, an approximation takes place between 

 the two points of attachment, so that the point more movable 

 at the moment approaches to the more fixed point. To this 

 rule all the movements of the tongue can be referred. The 

 movements of the tongue dispose the food for being ground 

 between the teeth, and are afterwards concerned in collecting 

 the masticated morsels together and conveying them to the 

 back part of the mouth in order to be swallowed. The tongue 

 is also concerned in deglutition, and forms a canal through 

 which the water passes when the animal drinks. 



