ACADEMY OF SCIENCES] BIOGRAPHY 5 



quent work. In the dissertation he calls attention to the fact that stimulation of certain afferent 

 nerves, such as the superior laryngeal, the splanchnic, and the second branch of the trigeminal 

 causes a contraction of the expiratory muscles and simultaneously an inhibition of the inspiratory 

 muscles, while stimulation of the vagus nerve, on the other hand, causes a reflex contraction 

 of the diaphragm and inspiratory muscle, together with an inhibition of the external oblique 

 muscle of the abdomen, an expiratory muscle. For the muscles of respiration, therefore, the 

 arrangement is such that reflex stimulation of the inspiratory muscles is accompanied by reflex 

 inhibition of expiratory muscles and vice versa. He goes on to assume that a similar reason- 

 able arrangement must exist in the case of antagonistic muscles in other parts of the body, for 

 example, with the flexors and extensors of the limbs, if they are to act most efficiently in locomo- 

 tion. Some ten years later Sherrington gave the necessary demonstration that this interrelation 

 does hold with the muscular antagonists of the limbs ; the contraction of an extensor is accom- 

 panied by a relaxation of its opposing flexor and vice versa. He designated this relationship 

 under the term of "reciprocal innervation," without apparently being aware of Meltzer's 

 similar views. 



Meltzer meanwhile had been accumulating further data bearing upon his generalization. 

 In his paper upon "The self-regulation of respiration," read before the American Physiological 

 Society in 1889 and published in the New York Medical Journal and under a different title in 

 the Archiv fur Physiologie, he describes experiments intended to show that two kinds of afferent 

 fibers exist in the vagus nerve, one exciting and the other inhibiting inspiratory movements. 

 He used this view to modify the Hering-Breuer theory of the self-regulation of the respirations 

 by assuming that the expansion of the lungs stimulates simultaneously both sets of fibers. 

 The resultant effect, as in the case of the simultaneous stimulation of the motor and inhibitory 

 fibers of the heart, is a dominance of the inhibitory action, thus arresting the inspiration and 

 bringing on a passive expiration, but subsequently the excitatory effect, which, like that due 

 to tbe accelerator fibers, has a long after action, comes into play and starts a new inspiration. 

 In his first general paper on inhibition (New York Medical Journal, 1899) this idea of a combined 

 action of opposing processes is extended by the citation of numerous instances taken from physi- 

 ological literature and is expanded into a general theory which makes inhibition a universal 

 property of living matter. "I entertain and defend the view that the phenomena of life are not 

 simply the outcome of the single factor of excitation, but they are the result of a compromise 

 between two antagonistic factors, the fundamental forces of life, excitation and inhibition." 

 That is to say, whenever a tissue is stimulated two different processes are aroused, one 

 leading to the functional activity and one to the suppression of this activity. As to the nature of 

 these processes he does not speculate to any extent. He was not satisfied with the Hering-Gaskell 

 conception, according to which excitation follows or is an expression of catabolic changes while 

 inhibition is the accompaniment of processes of an anabolic or assimilative nature. He goes 

 only so far as to assume that the two processes involve the potential and kinetic energies possessed 

 by the system, and that while excitation facilitates the conversion of potential to kinetic energy, 

 inhibition hinders or retards this conversion, the two processes being compared to the turning 

 on and off of a stopcock. Nor was he satisfied with Sherrington's term of reciprocal innervation 

 to describe the general relations he had in mind. Unfortunately, perhaps, he had not proposed 

 any concrete designation in the beginning to express the interplay of these opposing processes, 

 but later, stimulated no doubt' by Sherrington's example, he did attempt to find a suitable 

 descriptive phrase. 



In his second general paper on inhibition (Medical Record, 1902, page 881), he suggests the 

 term "law of crossed innervation," an expression used by von Basch and Ehrmann to describe 

 the opposed activity of the longitudinal and crossed musculature of the intestines. Later still, 

 in a paper in the Archiv fiir Verdauungskrankheiten, 1903, Volume IX, page 450, he modifies 

 this to the " law of contrary innervation." But he did not succeed in establishing either of these 

 variations upon Sherrington's nomenclature in current physiological literature. He no doubt 

 felt, and very justly so, that he should have had some of the credit for establishing this general 

 physiological law. His own plea for priority in the matter is given in a footnote to a paper 

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