Rejiexes, etc., of Mammalian Nerve-muscle. 



249 



Fig. 3. — Upper curves. Three break-shock reflexes (tibialis anticus, spinal cat) from 

 internal saphenous at coil distances marked on the figure. Lower curves, a maximal 

 twitch by break-shock to motor nerve at 20 cm., and a "supramaximal response" 

 by break-shock at 15 cm. coil distance. Time'marked by 100 d.v. fork. Isometric 

 "fall " myograph. Motor-nerve threshold at 70 cm. 



these experiments, that is, at times varying from four hours to twenty-eight 

 days after spinal transections at levels between the 9th thoracic and the 2nd 

 lumbar segments of the cord. But, as shown previously (2), (7), (8), the 

 description cannot be carried over with security to the decerebrate prepara- 

 tion. In this latter the reflex threshold is higher (7), (8), the reflex contrac- 

 tion is less strong and runs a different course (2), (7), and the latent period is, 

 in my experience, considerably longer. These differences from the " spinal 

 reflex are instanced in the records given in fig. 5. The latencies are as long as 

 some of those found by Jolly (11), with action currents, for the contra-lateral 



16 cm. 



— 15 cm. 



Fig. 4. — Similar to fig. 2, but with slower travel of the 

 photographic plate : time ordinates mark i sec. The 

 break-shock reflex contraction, A, evoked from internal 

 saphenous nerve, though of less crest-height than the 

 supramaximal responses, B, C, is of much longer dura- 

 tion. For A, break-shock at 22 cm. coil distances ; for 

 B and C, break-shock at 15 cm. and 16 cm. respec- 

 tively. 



