860 MUSCLES. 



Some of the muscles arise by a single head, and are inserted 

 into one point. Some few arise by a plurality of heads, but 

 have a single insertion, as the biceps flexor of the arm, and of 

 the thigh; others, again, have a single head, but a plural inser* 

 tion, as the flexors of the fingers and of the toes; others, again, 

 have multiplicate heads and multiplicate insertions, as the mus- 

 cles of the back. 



The most simple muscles are such as have their fibres run- 

 ning in the direction of the length of the muscles, of which 

 there are many examples, as the sartorius, the biceps flexor 

 cubiti, the semi-tendinosus, and others. Others, again, have 

 their fibres running obliquely from a tendon or a bony origin 

 on one side of the muscle, to a tendon on the other, as the se- 

 mi-membranosus, the peronei, &c.; these are called musculi 

 semi-pennati. Others have a long tendon in the centre, to 

 which the fibres converge obliquely, forming an angle with 

 each other; they are the penniform, (musculi pennati.) Others, 

 again, are formed of a congeries of smaller muscles, the fibras 

 of which run in different directions and are intermixed with 

 tendinous matter, as the deltoid and the subscapular. As the 

 strength of a muscle depends upon the number of its fibres, 

 those whose fibres go obliquely are stronger than if their fibres 

 had run longitudinally. 



CHAPTER IV. 



OF THE TENDONS, (TENDINES.) 



THE tendinous extremities of muscles, present themselves 

 under two general shapes: one is funicular, or like cords, va- 

 rying in shape from cylindrical to paraboloid; the other is 

 spread out into a membrane, and resembles an aponeurosis. 

 They both adhere with great tenacity to the muscular fibres, 

 so as to have induced, erroneously, the opinion of absolute con- 

 tinuity: but maceration and boiling will separate them, and the 

 course of the fibres is different even to the naked eye; besides 

 the very obvious difference in colour, in consistence, and in 

 vital properties. 



