234 Mayoiv 



added to it, has yet undergone contraction as to 

 length, and besides, rises at / into a tumour. But, 

 indeed, it is hardly to be believed that muscular fibres 

 should be ready to start this sort of motion unless 

 some new matter were added for that end ; for, as the 

 structure of an uncontracted muscle is lax, it would 

 seem that the fibre b^ d^ in its contraction should not 

 be carried outwards towards /, but rather, on the 

 contrar}^, should go inwards. Again, if the contracted 

 muscle is of the same size as before, and if no new 

 matter has come to it, how is it that in its contraction 

 it becomes so hard and tense, as any one can find out 

 in himself by placing his hand on a contracting 

 muscle ? And finally, what indeed could contract the 

 fibres and cause a charage of this sort in the muscle if 

 nothing flowed into it ? Nay, it is quite evident that 

 some new matter brought by the channel of the 

 nerves is required for starting the contraction of the 

 muscle, inasmuch as, if the nerve distributed to a 

 muscle be cut, the contraction of that muscle becomes 

 impossible. 



I confess, for my part, that if we concede the arrival 

 of new matter for accomplishing the contraction of 

 the muscle, its contraction can be produced by a 

 mere change of its shape ; as will be seen in the figure 

 referred to, in which, when the muscle a^ 3, c, d^ is 

 inflated by the motive influx, it necessarily follows 

 that the fibres a^ c^ and 3, d^ are brought towards a 

 position at right angles to the tendon c, d^ which we 

 assume to be fixed, and that the other, the more 

 mobile tendon, is drawn outwards so that the inflated 

 muscle will be c^ d^ e^ i. For that muscle could, by 

 no other change produced in it, be enlarged for the 

 reception of new matter and be thus inflated. But 

 while the muscle is thus changed as to shape, it 



