116 



tongue, change the action in a way which will be ex- 

 plained further on. 



M. Sterno-glossus Inferior. 



This muscle acts together with the Sterno-glossus Supe- 

 rior. They both also unite to form the round muscle 

 mentioned above. It arises with the Sterno-glossus Su- 

 perior, from the under side of the sternum, and is inserted 

 into the base of the posterior part of the tongue. It is 

 very small, with numerous slips of insertion. A slip from 

 the muscle, or a small one bound up with it and the 

 Sterno-glossus Superior, becomes a separate muscle, pass- 

 ing from the larynx to the tongue, and may be known as 

 a Laryngoglossus. 



M. Myloglossus. 



The Myloglossus is a very complicated muscle and may 

 conveniently be divided into two parts. The first and 

 most superficial part is very thin and arises from the raph6 

 in the middle line, midway between the rami of the lower 



J aw -. 



The origin from the raphe is of course connected with 



the deeper parts of the Myloglossus. The superficial por- 

 tion is inserted into the lower maxillary bone, just below 

 the Coronoid process, by means of a small tendon. This 

 part of the muscle is fan shaped. A second part of the 

 Myloglossus is much larger, and more important than the 

 one already mentioned. It arises from a common raphe, 

 with its fellow of the opposite side, along the mid-line of 

 the throat, together with an M. Annulus Inferior. It is 

 inserted upon the under side of the skull, in a line extend- 

 ing from the anterior portion of a styloid region, to a point 

 under the angle of the jaw. The length of the attachment 

 to the skull is 20 mm . In addition to these two parts of the 



