8 94 THE CEREBELLUM. 



conjugate rotation of the eyeballs around their anterior-posterior axes. 

 With the movement of the eyeballs occurs constriction of the pupils, 

 chiefly of the homonymous eye, and turning of the head in the same 

 direction with the eyes. Movement of the limbs of the same side as the 

 excitation was also elicited. In the pigeon he obtained drawing of the 

 head backward and to the homonymous side, flapping of the homony- 

 mous wing, and flexion of the homonymous leg. In the carp he found 

 curving of the tail to the homonymous side, spreading of the homony- 

 mous fins, and movement of the homonymous eye. He pointed out 

 that the relation between the cerebellum and the musculature of limbs 

 and trunk is therefore, unlike that between the latter and the cerebrum, 

 an homonymous one; and similarly that cerebellar connection witli the eye 

 muscles is, as regards relations of laterality, the reverse of that possessed 

 by the cerebral hemisphere. His experiments appear to have been the 

 earliest to decide these important points. Hitzig, 1 Nothnagel, 2 and 

 Dupuy 3 also have obtained definite muscular reactions by localised 

 excitation of the cerebellum, and believe the excitations originate 

 sensations of a painful character. 



It has been found, independently by M. Lowenthal and myself, 4 that 

 excitation of the cerebellum, as of various other parts of the central 

 nervous system, can not only excite contraction of the muscles, but can 

 inhibit contraction. Certain forms of tonic spasm in various parts of the 

 body relax on excitation of the cerebellar surface. When " decerebrate 

 rigidity " has developed, it can be inhibited by faradisation of the anterior 

 (cerebral) surface of the cerebellum at points (in the monkey) over a 

 large area extending from near the middle line far out toward the lateral 

 border of the cerebellar surface. 6 Faradisation at these points causes 

 immediate relaxation of the rigid neck and tail muscles, and of the 

 rigidly fixed joints of the limbs, especially of the fore-limb, and especially 

 of the same side as the site of excitation in the cerebellum. 



Lesions of the cerebellum. — The earliest experiments in which 

 successful recovery was obtained from ablation of the cerebellum 

 (and cerebrum) in higher animals, seem to be those by du Yerney 

 in 1697. 6 He noted that there remained still some " use of sense." 

 Little progress was then accomplished until Eolando 7 (Sassari, 1809); 

 from that time onward a number of workers followed in this field. 8 

 Flourens affirmed that removal of even considerable portions of the 



1 " Untersuch. u. d. Gehirn," Berlin, 1874. 



2 Centralbl. f. d. med. Wissensch., Berlin, 1876. 



3 Corrupt, rend. Soc. de biol., Paris, 1885-1887. 



4 Sherrington, Proc. Roy. Soc. London, 1896, vol. lx. p. 382 (in abstract) ; Lowenthal 

 and v. Horsley, ibid., 1897, vol. lxi. p. 20. My observations were made on the elbow, 

 knee, neck, and tail of the monkey, cat, and rabbit ; Lowenthal and Horsley's on the 

 elbow of the dog. 



5 Sherrington, Journ. Physiol., Cambridge and London, vol. xxii. p. 319. 



6 Phil. Trans., London, vol. xix. p. 226. 



7 "Saggio sopra 1. vera struttura d. cervello, etc." 



8 Between du Verney and Rolando the chief experimenters studying destructive lesions 

 of the cerebellum were : — Lorry, Hist. Acad. roy. d. sc, 1749, tome iii. p. 344 ; Haller and 

 his pupils, especially Zimmermann and Zinn, and Saucerotte later in 1769. After Rolando 

 the more important contributions in the same line have been the following, and chiefly on 

 them the present section of this article is based:— Flourens, "Rech. exp., etc. , " Mem. Acad, 

 d. sc. de I'lnst. de France, Paris, 1822 ; Magendie, Journ. de physiol. cxpdr., Paris, 1825, 

 tome iv. p. 399 ; Desmoulins, " Anat. des systemes nerv.," Paris, 1825 ; Hertwig, " Exper. 

 qupedam," Inaug. diss., Berlin, 1826, S. 151 ; Serres, "Anat. compar. d. cerveau appliquee 

 a la physiologic," Paris, 1826 ; Bouillaud, Arch. gen. de med., Paris, 1827, tome xv. p. 64 ; 



