LATERAL SEMISECTION OF THE CORD. 863 



section of the column. 1 Schiff concluded that the stimuli, even when 

 such as calculated to evoke painful sensations, no longer evoke signs 

 indicative that any painful quality attaches to the reactions manifested. 

 Herzen 2 and others confirm this. Chiefly for this reason the long 

 dorsal-column path is often considered " tactual." Anatomists 3 have 

 written of it as "reserved for conscious sensation." Some authorities 

 treat it as acknowledgedly connected with muscular sense. Its nerve 

 fibres seem in the monkey to give reflex collaterals to the motor 

 root cells of the hand and foot muscles especially, for electrical excitation 

 of the path at the top of the cord excites those movements. The func- 

 tion of the long path must be considered still unproven ; my own opinion 

 inclines, to relate it to muscular rather than to tactual sense. There is 

 much in favour of H. E. Bering's view that it serves to conduct 

 centripetal impulses which, arising in the apparatus of movement, 

 regulate by unconscious reactions the movements of the skeletal 

 musculature. 4 



Concerning the ventro-lateral columns, there is good evidence that in 

 their lateral portion runs down the path concerned with the direct regula- 

 tion of muscular contraction, while in the same region headward, runs the 

 path from all sensory apparatus in its first relay after the first synapse. 

 WoroschilofTs experiments 6 showed that, at the level of the last thoracic 

 vertebra, this lateral region is patent to downward impulses that move 

 the hind-limb for progression, and upward that connect its skin with 

 encephalic nervous centres, so as to allow reactions indicative of 

 unimpaired sensitivity of the limb's surface. When at the lowest 

 thoracic level the only part of the cord remaining unsevered is the 

 lateral region of each ventro-lateral column, the rabbit, as judged by its 

 movements and its reactions to sensible stimuli, is to all appearance 

 still in a normal state. In the lateral region also, and apparently 

 exclusively in it, ascend paths for vasomotor reflexes from the sciatic 

 nerve. Direct faradisation of the ventro-lateral column 6 in areas as 

 circumscript as practicable produces, according to the locality of 

 application to the face of the section, movement of the wrist, fingers, 

 trunk, hip, knee, and digits, all on the homonymous side. To evoke 

 movements is far easier from certain spots of the cross-section than 

 from others. The easiest foci lie in the ventral root-zone, and the next 

 easiest in the dorsal half of the lateral column. The path descendent 

 from each half of the bulbar respiratory centre lies in the homonymous 

 lateral column, 7 and in the phrenic region either descendent path gives 

 branch paths across to the contralateral motor cells. 8 The descending 

 path connecting the brain with the lumbo-sacral " centre " for the motor 

 nerves of the urinary bladder lies similarly in the dorsal part of the 



1 Schiff, "Lehrbuch," 1858 ; also " Recueil d. mem.," Lausanne, 1896, tomeiii. ; Longet, 

 " Systeme nerveux," Paris, 1860, tome i. p. 274 ; Eigenbrodt, " Ueber d. Leitungsgesetze i. 

 Riickenm.," Giessen, 1849. 



2 Cf. Note to French edition of Waller's "Human Physiology," Paris, 1898. 



3 v. Kolliker, "Handbuch d. Gewebel. d. Menschen," Leipzig, 1896, 6te Aufl., Bd. ii. 

 S. 116; Waldeyer, Deutsche med. Wchnschr., Leipzig, 1891, S. 61. ; v. Lenhossek, " Der 

 feinere Bau des Nervensystems, " Berlin, 1895, S. 397. 



4 Frag. med. Wchnschr., 1896, Bd. xxi. S. 41; also Leyden, Virchoiv's Archiv, 

 1869, Bd. xxxvii. ; Frenkel, Neurol. Centralbl., Leipzig, 1897, Bd. xvi. S. 688 ; Miinzer 

 and Wiener, ibid., 1899, Bd. xviii. S. 21. 



5 Arb. a. d. physiol. Anst. zu Leipzig, 1874. 



6 Gad and Flatau, Neurol. Centralbl., Leipzig, 1897. 



7 Schiff, "Lehrbuch," 1858 ; Langendorff. Wertheimer, Gad and Marinesco, later. 



8 Porter, Journ. Physiol., Cambridge and London, 1895, vol. xvii. p. 455. 



