270 MUSCLES 



A bellied muscle, dissected from the leg of a rat or frog, 

 illustrates clearly the gross structure of a muscle. Exam- 



FiG. lie.— Flat muscles of the back. 



ination of such a dissected muscle shows it to be entirely 

 inclosed in a connective tissue sheath called the -perimy- 

 sium. This sheath is thin and transparent, and, at the 



