SOME NERVE-MUSCLE EXPERIMENTS ON THE 

 FROG {Rana Catesbiand)} 



HOWARD AYERS. 



The experiments herein recorded have to do with the in- 

 fluence of the rate of stimulation upon the propagation of the 

 results of electrical stimuli in peripheral nerves. This topic 

 has been the subject of recent investigations by several physi- 

 ologists, among whom are Dr. F. H. Hooper ^ and N. Weden- 

 sky,^ who, as a result of their researches, consider the rate of 

 stiniidation to be as important a factor affecting the propaga- 

 tion of nerve force as the intensity of the stimulus is con- 

 ceded to be, I shall first describe the experiment on the 

 frog's larynx, then those on the antagonistic muscles of the 

 leg of the animal. 



For an account of the physiology of the mammalian larynx 

 the reader is referred to Dr. Hooper's excellent resume in 

 the above mentioned paper (i) where the experimental results 

 of all the studies of this structure — reaching back some 

 centuries — are recorded. From Dr. Hooper's papers it is 

 clear that even closely related tracheate vertebrates, e.g. the 

 dog and the cat, do not agree in the responses made by the 

 laryngeal muscles to similar electrical stimuli, all other con- 

 ditions of the experiments being so far as known (and they 

 were intended to be) the same. 



Owing to this condition of the subject, these experiments, 

 which were begun at the suggestion of Prof. Bowditch, are 



1 Performed in the Physiological Laboratory of the Harvard Medical School, 

 1888-89. 



2 F. H. Hooper, M.D. The Anatomy and Physiology of the Recurrent Laryn- 

 geal Nerve. The N. Y. Med. Journ., 1887. 



The same. Effects of Varying Rates of Stimulation on the Action of the 

 Recurrent Laryngeal Nerves, ib., 1887. 



3 N. Wedensky. Ueber die Ursachen des Ritter-Rolletschen Phanomens am 

 Fusse des Froches. Centrlblt. fiir Physiologie, I, 1887. 



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