Traiismi.ssion of Reflex Impulses in Spinal Cord of the Frog 253 



I must confess, however, that this analysis in terms of synapse delay 

 does not give me much satisfaction, for it would require us to say that the 

 spinal delay caused by strychnine occurs in the first and not in the second 

 synapse. And I still prefer, in the absence of further guidance, to limit 

 myself to the conclusion I drew in 1885,^ to the effect that the prolongation 

 of reflex time by strychnine is principally caused by a block or functional 

 obstruction at the junction of aflerent fibre with spinal cell. 



I have said " principally " where it might have appeared permissible to 

 say " exclusively." On attentive consideration of the analysis of flg. 4, the 

 whole added delay appears to belong to the first synapse, or — as I prefer 

 to say — to the aflerent side of the centre, and there is no appreciable re- 

 tardation attributable to the second synapse; i.e. the excitatorj- process 



Fig. 1. — Norma 



(1) Direct muscular contraction. The lost time is 0-008 sec. 



(2) Muscular contraction caused l)y a single break shock to 

 upper part of tlu- spinal cord. The lost time is 0-016 sec. 



(3) Muscular contraction (reflex) caused liy a single break 

 shock applied t« the .skin of the arm of the game side. The 

 lost time is uOlCi sec. 



passes from cell to cell within the cord with normal rapidity. But in 

 extreme cases of delay where, as I have observed, the reflex time maj' reach 

 ^th sec, the ordinary j j\o^h sec. occupied by transmission in the cord by 

 one cell to another (or by one synapse to another) is considerably exceeded. 

 Thus in the case of fig. 80 of my 1885 paper the values are as follows : — 



Simple reflex, 0-200. 

 Crossed reflex, 0-228. 



Analysis in this case (which I may mention in passing gives the highest 

 values I ever observed) gives in place of the normal yooth sec. delaj' for 

 the first cell (or synapse) the enormous value of nearly ,^foths sec, and in 



• Briti.sh Medical Journal, "Report on KxpeiiuK-nts in the Proce.ss of Fatigue 

 and Recovery," 25tli July 1885. 



