978 CUTANEOUS SENSATIONS. 



negative, in spite of employment of strong " painful " stimuli, conduction of 

 pain impressions does not travel along the dorsal white columns. It appears 

 probable that the path for pain involves a spinal relay cell, or several such, 

 instead of the long direct root-ganglion path. 



Budge concluded that a powerful stimulus produces (1) a local reflex, by short 

 fibres entering the grey matter, in the immediate vicinity of the entrance of the 

 afferent root in the cord ; and (2) a " feeling " of pain from centres in the bulb, 

 reached by conduction through arid up along the grey matter of the spinal 

 cord. That the path of upward conduction for pain lay in the spinal grey 

 matter is a conclusion in which, on the basis of his own experiments, he 

 follows Stilling, Schiff, and Browii-Sequard. 1 



Schiff 2 and also Budge 3 concluded from vivisection experiments in which, 

 as the latter carefully points out, the character of movements is the only guide 

 that the observer has regarding the provocation of pain that only those fibres 

 of the afferent spinal roots provoke pain, which end soon after entering the 

 cord in the grey matter of the cord. Budge, especially, exhaustively examined 

 by irritation the various portions of the central nervous system, to determine 

 those which, when so examined, seem, as judged by the reactions, to provoke 

 pain. He obtained no evidence of painful reaction from the cerebral hemi- 

 sphere, including corpus striatum. The optic thalamus gave dubious indica- 

 tions, which Budge was inclined to attribute to experimental implication of the 

 neighbouring cerebral peduncle. The deeper and median parts of the corpus 

 quadrigeminum anterius, he concluded, could occasion severe pain, so also the 

 corpus quadrigeminum posterius. From the corpora quadrigemina to the lower 

 end of the fourth ventricle was a region, irritation of which always seemed to 

 evoke pain, unless the irritation were confined to grey matter. Removal of the 

 corpora quadrigemina on one side (after ablation of the hemisphere on that side, 

 which was unproductive of effect as regards pain) in the rabbit produced at first 

 marked diminution of sensitivity to pain on the same side of the body (rabbit), 

 followed by hyperalgesia on that side. 



Hence Schiff 4 wrote of the grey matter as "aesthesodic." Budge 5 

 describes, as an experiment for demonstrating the insensitivity of grey matter, 

 the pricking with a needle of the grey matter of the calamus scriptorius ; the 

 animal remains perfectly unmoved thereby, a touch on the adjoining white 

 matter evokes a violent reaction. 



Other experiments which bear on the central path of conduction in the 

 cord, are those in which various degrees of transverse and longitudinal section 

 of the cord have been performed. Stilling, Schiff, and Budge (see above) 

 believed that the impressions eliciting pain crossed to the grey matter, opposite 

 the side of their entrance, and ascended in it to the bulb. They were under 

 influence of Gerlach's supposed network of conducting fibres in the grey 

 matter. For them the grey matter was a continuum, as it is not now 

 believed to be. There is now no evidence of any but short fibres in the grey 

 matter, and any prolonged conduction up it, if possible, would involve transi- 

 tion across many synapses ; and every synapse probably introduces a resist- 

 ance, so that the resistance of such a path, if the path were possible, would 

 probably be enormously high. Experiments show the grey matter incapable 

 of conducting a long distance. 6 Brown-Sequard, 7 Ferrier, 8 and Aldren 



1 Oaz. med. de Paris, 1854, 1855. 2 " Physiologie, " Lahr, 1858, Bd. i. S. 242, etc. 



3 " Untersuch. ueber d. Nervensystem, " 1841, Bd. i. S. 10 ; and, finally, "Physiol. des 

 Menschen," Leipzig, 1862. 



4 Op. cit. 5 "Physiol. des Menschen, " Leipzig, 1862. 



6 Weiss, Sitzungsb. d. k. Akad. d. Wisscnsch. math.-naturw. CL, Wien, 1879, Bd. Ixxx. 

 S. 340. 



7 "Lectures on the Physiology and Pathology of the Nervous System," Philadelphia, 

 1860, p. 30 ; Journ. de I'anat. et physiol., etc., Paris, 1869, tome vi.; Lancet, London, 1868, 

 vol. ii. 



8 "Functions of the Brain, "London, 1886, p. 51 ; also Lancet, London, 1890, vol. i. p. 1416. 



