THE TENDONS. 287 



extreme branches of the arteries must necessarily wash away 

 the blood which was previously effused from the same 

 branches. 



The water with which muscles have been washed, appears as 

 if some blood had been mixed with it ; it contains albumen and 

 gelatine, with some fibrine, and a peculiar extractive substance, 

 as well as the red coloring matter. 



The substance of the muscle, when thus separated from the 

 above mentioned matter by washing, appears to be of the same 

 nature with the fibrine of the blood : and after boiling some time 

 in the water, it seems, like that substance, to consist of brown 

 insoluble fibres which are brittle when dry. 



When the great function of muscles is under consideration, 

 nerves appear of more importance than blood-vessels. 



The nerves appropriated to muscles of voluntary motion are 

 more numerous than those appropriated to any other parts, 

 except the organs of sense. They subdivide into very fine 

 fibrillae ; and it is the opinion of one of the latest observers, that 

 these fibrillae become soft and transparent, and finally blended 

 with reticular membrane which surrounds the muscular fibres. 



It ought to be noted that muscles are indued with great sensi- 

 bility,- and that the smallest puncture cannot be made in them 

 without exciting pain. 



Of the Tendons. 



Thus arranged, the fibres of muscles are most generally attach- 

 ed to tendons, which are inserted into the bones these muscles 

 are intended to move. They are also, in some cases, inserted 

 into tendinous membranes, and other parts necessary to be 

 moved ; but in all such instances these parts are perfectly pas- 

 sive ; and the motion in which they are concerned is altogether 

 produced by the contraction of the muscular fibres. 



The tendons appear to be formed of a continuation of the 

 cellular membrane which envelops the fibres of the muscles. 

 The ultimate construction of muscles was shown in page 283, 

 to consist of a multitude of filaments each one composed of a 

 linear series of the muscular molecules ; each of the molecules 



