THE PHENOMENON OF CONTRACTION. 



33 



gested by some that there are two different contractile substances in muscle, 

 one giving the usual quick contraction, known as a "twitch," the other the 

 slower contraction, which exhibits itself as tone or contracture.* 



The Effect of Rapidly Repeated Contractions. When a 

 muscle is stimulated repeatedly by stimuli of equal strength that 



* loteyko, "Travaux du laboratoire de Physiologic," Institut Solvay, 1902, 

 5, 229. 

 3 



