MUSCULAR SYSTEM. 219 



Properties of the Muscular System of Jlnimal Life. 



Q. For what are these properties remarkable? 



*/l. The muscles have slight physical and conspicuous 

 vital properties. You have heard that the muscles are 

 slightly elastic and soft. 



1. Properties of Texture. 



Q. What property of texture is most remarkable? 



t/#. Extensibility; and this is in the flexor or extensor, 

 as the one or the other may be passive. Extensibility is 

 confined to the muscular fibre, not extending to the ten- 

 dons. 



Q. What morbid phenomena remarkably illustrate this 

 property in the muscles? 



/?. The distention of the muscles with tumours, and 

 that in pregnancy. The aponeuroses have some influence 

 in preventing their distention in the extremities. 



Q. On what is contractility of texture, so conspicuous 

 in muscles, dependant? 



/?. Not on the action of the nerves, not entirely on life; 

 it is on the structure of the muscles that it essentially de- 

 pends/ 



Q. How do you distinguish contractility of texture in 

 the muscles from the vital forces? 



*ft. Between the extreme points of extension and flexion 

 of the moveable parts of the body there is a resting point, 

 or a middle one. To remove a limb from this point of 

 rest, animal contractility or a vital force must act on the 



