LASHLEY— CEREBRAL FUNCTION 251 



baum and Sherrington, 2 " C. and O. Vogt, 21 Lewandowsky and Sim- 

 mons, 22 Hoppe, 23 Cushing, 24 Franz, 23 and Leyton and Sherrington, 26 

 all points to the conclusion that primary excitability is limited to the 

 precentral gyrus and that sensory disturbances rarely result from lesions 

 confined to this area. 



These studies have defined the centrifugal function of the cells of the 

 precentral gyrus and have confirmed the view that the area is motor 

 rather than somesthetic. but in spite of the fairly general recent agree- 

 ment as to the location of "motor" area, there is a wide diversity of 

 opinion concerning the significance of the "motor" function. The area 

 is somehow concerned with the production of movement, but how it 

 acts and what kinds of movement it controls, are still debated points. 

 Ferrier 6 emphasized the "automatic" character of movements after 

 destruction of the motor areas and held that "All reactions not so 

 (automatically) organized, and still dependent upon conscious discrimi- 

 nation and exercise of attentive volition are effectually and permanently 

 annihilated." Munk 27 classified movements according to their somatic 

 distribution and maintained that small unilateral adaptive movements 

 ( Einzelbewegungen ) are permanently lost after destruction of the motor 

 areas. His definition of these movements is by no means clear, but 

 his accounts seem to imply that the movements had been learned, and 

 he denies that a dog can learn to give his paw after destruction of both 

 motor areas. Wagner 28 maintained that the chief function of the motor 

 areas is in learning, and that animals deprived of them are incapable of 

 forming any new habits. Bechterew 29 also refers to experiments lead- 



20. Grunbaum, A., and Sherrington, C. S. : Observations on the Physiology 

 of the Cerebral Cortex of the Anthropoid Apes, Proc. Roy. Soc. 72 B: 152-155, 

 1903. 



21. Vogt, C, and Vogt, O. : Zur Kenntnis der elektrisch erregbaren Hirn- 

 rindengebiete bei den Saugetieren, J. f. Psychol, u. Neurol. 8:277-456, 1907. 



22. Lewandowsky, M., and Simmons, A. : Zur Physiologie der vordern und 

 hintern Zentralwindung, Arch. f. d. ges. Physiol. 129:240-254, 1909. 



23. Hoppe, H. H. : A Critical Study of the Sensory Functions of the Motor 

 Zone (Pre-Rolandic Area) : More Especially Stereognosis, J. Nerv. & Ment. 

 Dis. 36:513-527, 1909. 



24. Cushing, H. : A Note Upon the Faradic Stimulation of the Postcentral 

 Gyrus in Conscious Patients, Brain 32:44-54, 1909. 



25. Franz, S. I. : Variations in Distribution of the Motor Centers, Psychol. 

 Monogr. 19:80-162, 1915. 



26. Leyton, A. S. F., and Sherrington, C. S. : Observations on the Excitable 

 Cortex of the Chimpanzee, Orang-Outan and Gorilla, Quart. J. Exper. Physiol. 

 11:135-222, 1917. 



27. Munk, H. : Ueber die Fuhlspharen der Grosshirnrinde, Sitzungsber. d. 

 Berlin Akad. Wiss., 1892, 679-723; 1893, 759-781; 1894, 823-833; 1896, 1131-1159. 



28. Wagner, V: Discussion in Neurol. Zentralbl. 24:1022, 1905. 



29. Bechterew, W. v.: Die Funktionen der Nervencentra, Jena 3. 1911. 



