238 Mayow 



tribute to the strength of the muscles and to the 

 more effective performance of their pull. Certainly 

 the fibrils, whether we consider their number, their 

 size, or their position, would seem much more fit for 

 bringing about muscular contraction than the fleshy 

 fibres. And this is further much confirmed by actual 

 inspection; for, so far as. I have ever been able to 

 attain in examination by vivisections, the fleshy fibres, 

 in the contraction of a muscle, as if attracted by the 

 transverse fibrils, seemed to come nearer one another, 

 and not to be themselves shortened, but to follow the 

 contraction of the fibrils. 



As to the fact that, in consequence of a ligature 

 being tied round each end of the fleshy fibres, 

 muscular contraction ceases and the fibre itself does 

 not, as it otherwise would, swell up, as has been noted 

 by the eminent Dr Willis, I think this due to the 

 interruption, by means of the ligatures, of the motion 

 of the blood and of the animal spirits, an inflow of 

 which is necessary for the contraction of the fibrils. 



CHAPTER III 



OF THE PARTICLES BY MEANS OF WHICH MUSCU- 

  LAR CONTRACTION IS EFFECTED ; AND IN THE 

 FIRST PLACE OF THE MOTIVE PARTICLES 

 BROUGHT BY THE BLOOD; INCIDENTALLY, OF 

 THE STRUCTURE AND USE OF MUSCULAR 

 FLESH 



In the previous chapter I have endeavoured to show 

 that muscular contraction is chiefly caused by the 

 fibrils. Let us now, in the next place, see by what 



