344 APPENDIX. 



locomotion are the muscles, or flesh, by which the bones 

 of all animals are surrounded. 



We copy the following definitions concerning the mus- 

 cular system from Hoblyn's Dictionary of Medicine, a 

 book which every student in the sciences should pos- 

 sess. 



Muscle, an organ of motion, constituting the flesh of 

 animals, and consisting of beaded, or cylindrical fibres, 

 which are unbranched, and are arranged parallel to each 

 other in fasciculi. In general, the name venter, or belly, 

 is given to the middle portion of a muscle, while its ex- 

 tremities are named the head and tail, or more commonly 

 the origin and insertion. Hence the term diastricus, or 

 two-bellied, triceps, or three-headed, &c. 



I. Properties of the Muscles. 



1. Contractility, by which their fibres return to their 

 former dimensions after being extended ; and, 



2. Irritability, by which their fibres shorten on the 

 application of a stimulus. 



II. Forms of the Muscles. 



1 . The muscles, like the bones, may be divided into 

 long, broad, and short; and each of these kinds may 

 present muscles, either simple, or compound. 



2. The simple, or those which have their fibres arranged 

 in a similar, or parallel direction. They are in general 

 bulging, that is, their transverse outline is more or less 

 inflated in the middle. The simple muscles are some- 

 times flat, as the sartorius. 



3. The radiated, or those which have their fibres con- 

 verging> like the radii of a circle, to their tendinous in- 

 sertion, as the pectoralis, one of the muscles of the 

 chest. 



4. Ventriform, or belly-shaped, which have their cen- 

 ter large, diminishing toward their tendons, or extremi- 

 ties, as the biceps, or two-headed muscles. 



What is the meaning of the word muscle ? What are the muscles ? What 

 are the properties of the muscles? What are the forms of the muscles? 

 What is a simple mnscle ? 



