48 



Buchanan 



Left Gastrocnemius. (Exp. 56 L.) 



Both the direct and reflex efiects were less strong (curves less steep) in 

 these records than in those taken with the other muscle, but they were 

 about equal to one another. Reflex effects somewhat longer than when 

 the muscle of the other side was recording. Contractions also not quite 

 as strong, but of somewhat longer duration. 



The left sciatic nerve in this preparation was more excitable than the right, 

 for both the crossed reflex and the uncrossed reflex could be obtained 

 with it in response to a stimulus of 500 units' strength. The uncrossed 

 reflex with this strength was recorded mechanically, but not electrically ; 

 it was quite as strong as with a current of 1000 or more units. Xo 

 reflex response of either kind could be obtained when the right sciatic 

 was excited by a stimulus of 500 units' strength. Unfortunately, I did 

 not, after cutting the left sciatic, try whetlier the muscle still responded 

 when so weak a stimulus as one of 500 units was applied to the 

 peripheral end — so that, although I did ascertain the contrary in the 

 case of the right sciatic, it cannot be stated with certainty whether it 

 was the nerve or cord of which the excitability varied. 



In four of these experiments [Nos. 4, 16, 42, 48] the crossed-reflex effect 

 was unobtainable when the experiment was begun, even when, as in the 

 two last, fairly strong reflex effects were being obtained in response to 

 excitation of the sciatic nerve of the same side as the recording muscle. 

 It was not until after respectively nine, three, ten, and nine same-limb 

 reflex responses had been recorded (in all four cases at least a quarter of an 

 hour later) that any response at all could be obtained when a single break 

 induction current, even one strong enough to be felt on the tongue, was 

 applied to the sciatic nerve of the opposite side. In Exps. 42 and 48, it 

 was not until after a second very minute dose had been administered, and 

 even then not for some ten minutes later, that a crossed-reflex eflect could 



