114 Mr. K. Sassa and Prof. C. S. Sherrington. Myogram of the 



that of the maximal twitch, but also by several other features of the 

 myogram. (1) The excess, often very great, of the duration of the reflex 

 contraction. It may persist for several times as long as does the maximal 

 twitch. (2) The incidence of the crest of the contraction, also when that 

 crest-height exceeds that of the maximal twitch, falls later after onset of 

 contraction in the reflex than in the twitch. (3) In the reflex contraction 

 there not infrequently ensues after the main crest a second, or even a third 

 contraction-crest, breaking the line of subsidence of the reflex, and of period 

 far too slow to be referable to the vibration-period of the recording apparatus. 

 (4) The ascent of the reflex myogram is sometimes in part of its course more 

 steep than is any part of that of the maximal twitch; this is difficult to 

 understand except as due to summation of repetitive contraction-waves in 

 individual muscle-fibres. It sometimes occurs as early as the 15th a in the 

 course of the contraction. 



4. Reflex contraction of tibialis anticus is readily elicitable by a single 

 induction shock applied to the skin of the limb, e.g., to the skin of the foot. 

 "We have compared the isometric myograms of this reflex contraction (fig. 4) 

 with the maximal twitch evoked in the same preparation from the motor nerves. 



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4. — Reflex contractions of tibialis anticus (spinal preparation) in response to single 

 break-shock applied to skin (unipolar) ; top line, three myograms given by break- 

 shock, coil at 15 cm., applied respectively to skin of first digit, to central end of 

 popliteal nerve, and to distal end of peroneal nerve (maximal twitch) ; bottom line, 

 reflex from skin of first toe, coil at 10 cm. compared with motor nerve stimulation 

 also at 10 cm., i.e., maximal twitch. Time in 0"01". 



To evoke the reflex the break-shock was applied as follows : A broad copper 

 plate was fastened to the sole of one forefoot, a layer of cotton-wool soaked in 

 strong salt solution intervening between the skin and the plate. For the 

 stigmatic electrode the point of a small entomological gilt pin, attached to 



