THE HISTORICAL DEVELOPMENT OF NEUROPHYSIOLOGY 



35 



which Hall gave to the Zoological Society of London 

 in November 1832, there is, however, no full descrip- 

 tion of the reflex arc nor does he use these terms. The 

 emphasis is on "a function of the nervous system . . . 

 distinct from sensation and \oIuntary or instinctive 

 motion," being a "property which attaches itself to 

 any part of an animal, the corresponding portion of 

 the brain and spinal marrow of which is entire." 



The attack was pursued by others-" with great 

 bitterness and its leaders engaged in such unworthy 

 acts as checking on library slips to prove that Hall had 

 borrowed Prochaska's book. (The slips however post- 

 dated Hall's original publications.) To the modern 

 worker the battle seems puerile and undignified and 

 one regrets that its protagonists did not spend the 

 time on experiment instead of polemics.-' Of the men 

 for whom priority was being claimed, Prochaska was 

 dead and it is noticeable that Miiller, a truly gieat 

 man, after making generous acknowledgement to 

 Hall in his Handbuch stood aloof from these bicker- 

 ings. 



In essence Marshall Hall's inajor contributions to 

 neurophysiology were, first (192), that sensory impres- 

 sions coming into the medulla spinalis had far reach- 

 ing effects in the nervous system in addition to the 

 segmental efTector response,'" secondly the recognition 

 that although reflex activity took place at a spinal 

 level it could be influenced by the wilP^ and thirdly, 

 the relationship of this fact to the exaggeration of 

 reflex response on removal of the brain (193). These 

 are not the only areas in which he anticipated 

 Sherrington. He gave a preliminary glimpse of the 

 stepping reflex, "In the actions of walking in man, I 

 iinagine the reflex function to play a very considerable 

 part, although there are, doubtless facts which 

 demonstrate that the contact of the sole with the 

 ground is not unattended by a certain influence upon 

 the action of certain muscles." 



Marshall Hall introduced the word 'arc' to describe 

 the refle.x pathway. Many of his other terms have, 

 happily, not been retained by physiologists, for he was 

 a great lover of neologisms, as his definition of the 

 arc shows: "the existence in Anatomy and Physiology, of 

 a continuous Diastaltic Nervous Arc including an 

 Esodic Nerve, the Spinal Centre and Exodic Nerve in 



192. Hall, M. On the reflex function of the medulla oblongata 

 and medulla spinalis. Phil. Trans. 123: 635, 1833. 



193. Hall, M. On the true spinal marrow, and on the excito-motory 

 system of the nerves. Lectures given before the Royal So- 

 ciety, privately printed, 1837. 



essential relation and connection with each other — 

 and of a series of such Arcs. . . ." (194). (One recog- 

 nizes here that Queen Victoria had a rival among her 

 subjects in the use of italics.) 



One further contribution of Hall's at the conceptual 

 level should be noted. Implicit, if not explicit, in the 

 theories of the earlier physiologists was the notion 

 that in voluntary movement volition directed a 

 nervous influence towards the individually appropri- 

 ate iTiuscles. Hall pointed out that the will was inore 

 teleological and less specific in its action and not 

 "directed to any muscle or set of muscles, but to an 

 aim, object and purpose of their contraction" (195). 

 Hall's contributions were not evaluated as highly by 

 his contemporaries as they have been by later physi- 

 ologists, though he himself had no doubts as to how 

 they should be ranked; he stated that they were the 

 greatest advance in medical science since William 

 Harvey. 



The iinpact of the work of the physiologists on the 

 concepts of the psychologists was very great and so 

 disturbing that their literature was filled with contro- 

 versy for many years. Long before the concept of 

 reflex acti\ity was carried into the brain by Sechenov 

 to explain its higher functions, the psychologists were 

 in distress over the implication for 'sensation,' for 

 'consciousness' and for 'volition,' of the developing 

 knowledge of spinal reflexes. The most conspicuous 

 controversy was that waged between Eduard Pfliiger 

 (196), von Helmholtz's successor at the Physiological 



194. H.'VLL, M. Synopsis oj the diastaltic nervous system. Crocnian 

 Lectures, London, 1850. 



195. Hall, M. Memoirs on the Nervous System. London, 1837. 



196. Pfluger, Edouard (1829-1910). Die sensorischen Func- 

 tionen des RUckenmarks der Wirbelthiere nebsi einer neuen 

 Lehre iiber die Leitungsgesetze der Reflexionen. Berlin, 1853. 



''"Such as, for example, George, J. D. Contribution to the 

 history of the nervous system. Lond. med. Gaz- 22: 40, 93, 

 1837-1838. 



-' A full account of the controversy (though scarcely an 

 unbiased one) can be found in Longet, F. A. Traite d'Anatomie 

 de Physiologie du Systeme Nerveiix de I'Homme et des Animaux 

 Vertehres. Paris, 1842. 2 vol. 



''- "But the operation of the reflex function is by no means 

 confined to parts corresponding to distinct portions of the 

 medulla. The irritation of a given part may, on the contrary, 

 induce contraction in a part very remote." Phil. Trans. 123: 

 635, 1833. 



'' "The true spinal system is susceptible of modification by 

 volition. . . ." Memoirs on the .Nervous System. London, 1837, 

 part 2, p. 73. (This part of the observation was anticipated 

 bv Whvtt.) 



