THE HUMAN STRUCTURE 



Fir,. 104 



Functional adaptions of muscular fibres. 



are either short and thick, or else long ; it is therefore by pressing 

 one against another and by increasing the "mass" of muscles, 

 that the fibres increase their resistance. Thus a great number of 

 fibres are often compressed in a minimum space. The tendons 

 only act as sheaths, g (fig. 104), to receive the extremities of the 

 fibres ; they transform themselves into thin cords, C acting as 

 receivers for the insertion of oblique fibres, in such a manner that 

 these are found in a considerable number in a section perpendi- 

 cular to their direction. This adaptation, giving a maximum 

 .force in a rmnimun volume, is purely functional ( 86). 



70. The resistance to fracture and the elasticity of the 

 muscles has also been studied by Wertheim, on fresh corpses, 

 hence eliminating any unsuspected nervous influences. For the 

 sartorious muscle (of the thigh) he obtained. 



