Traiisniission-tiiue of Reflexes in Spinal Cord of Frot{ 



18 



from the measured time interval between the arrival of the direct and that 

 of the reflex eflect at the flrst recording spot of the muscle. 



Only when the current applied to the nerve to excite it was so strong, 

 or the part of the nerve to which it was applied of such a nature, that a 

 temporar}^ obstruction was produced under the kathode when the current 

 was broken, must a longer time be deducted for transmission in nerve when 

 the kathode was between the anode and the cord, and a shorter one (from 

 the measured interval between the two arrival-times in the particular 

 record) when the kathode was between the anode and the muscle. 

 Although there is no difiiculty in detecting a delay-producing moment 

 of this kind, and in measuring the time taken to overcome the obstruction 

 at the kathode by the impulse going straight to the muscle, there is a 

 slight uncertainty about the exact amount to be deducted for delay caused 

 by such obstruction to the impulse starting in the opposite direction. The 

 reason for this uncertainty may be best explained by introducing here the 

 measurements of records taken alternately with (relatively) strong ascend- 

 ing and descending induction currents (in a strychnine preparation) with 

 a view to elucidating the matter. 



Exp. 48. Nov. 27, 1906. Room temp. 16° C. One minim 0-01 per cent, 

 liq. strych. injected one hour before preparing nerve and muscle. 



Allowing Olo- for the extra 4 mm. of nerve traversed when the current 



