1912.] The Process of Excitation in Nerve and Muscle. 503 



additional support for the conception that the electrical concomitant of the 

 nervous impulse may under certain conditions fail. 



Quite recently Ellison* has described a series of experiments from which 

 he draws the conclusion that an electric response does not necessarily 

 accompany a nervous impulse. A motor nerve is treated with cinchonamine 

 hydrochloride and stimuli are applied within the region so treated. It is 

 found that though the muscle contracts when the nerve is stimulated, no 

 trace of an electric response is shown by a galvanometer connected with 

 a pair of electrodes on the nerve. 



Herzenf and EadzikowskiJ attacked the problem in the reverse way, 

 bringing evidence to show that there may be a marked electric response in 

 a nerve along which no propagated disturbance is travelling. Their method 

 was essentially to show that a nerve under the influence of various abnormal 

 conditions would respond to a stimulus with an electric response though no 

 contraction of the muscle resulted. They concluded that the presence of an 

 electric response was no necessary indication that a nervous impulse was 

 present. These experiments were severely criticised by physiologists both as 

 to their technique and as to their interpretation. Wedensky§ and Boruttaul! 

 repeated the experiments and called attention to sources of actual 

 experimental error ; it would, however, be superfluous to enter now into the 

 details of that controversy, since recent experimental work has brought to 

 light facts which seem to invalidate the principle upon which the method 

 was founded. Herzen and Eadzikowski relied for their proof that no 

 nervous impulse passed along the nerve on the fact that the muscle did not 

 contract. To this inference it was very naturally objected that perhaps the 

 junction between nerve and muscle had shared the abnormal influences 

 which had been brought to bear upon the nerve, and had become impassable 

 to the nervous impulse. Eadzikowskilf was careful to exclude the possibility 

 of any such gross change in the junction between nerve and muscle ; but 

 recent work has shown that even in a nerve and muscle recently excised and 

 kept under the best possible artificial conditions the junctional region will be 

 found to offer a certain resistance to propagation. For example, Adrian 

 and I found evidence that in an apparently normal preparation there may 

 often be some nerve-fibres which fail to transmit a single propagated 



* Ellison, 'Proc. Physiol. Soe.,' January, 1911 ; ' Journ. Physiol.,' 1911, vol. 42, p. i; 

 Journ. Physiol.,' 1911, vol. 43, p. 28. 



t Herzen, ' Centralbl. f . Physiol.,' 1899, vol. 13, p. 455. 



X Eadzikowski, ' Arch. f. d. ges. Physiol.,' 1901, vol. 84, p. 57. 



.§ Wedensky, ' Arcb. f. d. ges. Physiol.,' 1900, vol. 82, p. 134. 



|| Boruttau, ' Arch. f. d. ges. Physiol.,' 1901, vol. 84, p. 325. 

 1" Radzikowski, loc. cit., and 'Centralbl. f. Physiol.,' 1901, vol. 15, p. 273. 



2 N 2 



