742 THE CEREBRAL CORTEX. 



when this is strong the head is drawn slightly to the side." 1 This 

 muscle is also called into action in expressing sudden terror. 



Stimulation below the centres above described produced, in Terrier's 

 experiments, opening of the mouth with protrusion and retraction of 

 the tongue, the protrusion being obtained more anteriorly, the retraction 

 more posteriorly. The movements were bilateral, and occasionally 

 repeated even some time after the electrodes were withdrawn. 



Subsequent observers have for the most part corroborated these state- 

 ments of Terrier, and have added the following facts : (1) Stimulation of 

 the upper part of the area, close to its upper boundary, produces, besides 

 the movement of the opposite angle of the mouth, also closure of both 

 eyes, 2 but especially the opposite one. 3 (2) Movement of the tongue 

 may be obtained even from the upper part of the area (thus showing a 

 very extensive representation of this organ) ; here it takes the form of 

 protrusion towards the opposite side, and may be combined with 

 bilateral movements of the cheeks, 4 whereas, over the lower part of 

 the face area, retraction of the tongue is more common. In producing 

 the lateral movements of the tongue, the same muscles on the two sides 

 are not called into play ; so that, although there is bilateral contraction 

 it is not symmetrical. The cheek movements are more generally and 

 easily obtained over the lower part of the area, and especially over 

 the posterior part of the lower end of the ascending frontal, and over 

 the lower end of the ascending parietal gyrus. They are there com- 

 bined with rhythmic masticatory movements of the lower jaw and 

 tongue, and with movements of the throat such as are made in 

 deglutition. (3) Stimulation of the anterior part of the lower end of 

 the ascending frontal convolution produces strong adduction of both 

 vocal cords, 6 but abduction of the cords is not obtainable from cortical 

 stimulation in the monkey, although it can be obtained in the cat and 

 dog. 6 



Destruction or removal of the facial area 7 produces paralysis of 



1 Ferrier, "Functions of the Brain," 2nd edition, p. 242. 



2 Schafer with Horsley, Festsclir. f. 0. Liidwiy, Leipzig, 1887, S. 280. 



3 Beevor and Horsley, Phil. Trans., London, 1894, B. See on the subject of the 

 cortical representation of the orbicularis oculi, Ziehen, Arch. f. Physiol., Leipzig, 1899, 

 S. 158. 



4 Horsley and Schafer, loc. tit. Beevor and Horsley, foe. cit., also obtained a peculiar 

 rolling movement of the tongue, with the dorsum turned to the opposite cheek. 



5 Semon and Horsley, Brit. Mcd. Journ., London, 1889, vol. ii. p. 1383 ; and Phil. 

 Trans., London, 1890, B, p. 187. 



6 Bisien Russell, Proc. Roy. Soc. London, 1895, vol. Ivii. p. 237 ; cf. also J. Brockrert, 

 Flandre med., tome xi. p. 769 ; and Klemperer, Arch.f. Laryngol. u. fihinol., Berlin, 1894, 

 vol. ii. S. 329. Adduction of the vocal cords from cortical excitation was first obtained in the 

 dog by H. Krause, on stimulation of the base of the precrucial gyrus, where this is con- 

 nected with the anterior composite gyrus (Arch. f. Physiol., Leipzig, 1884). Bilateral 

 removal of the part in question was found by H. Krause to produce marked alteration in 

 or even abolition of the bark, growling or whining sounds only being produced. This 

 confirms the prior observations of Soltmann (Jahrb.f. Kindcrh., Leipzig, 1875, Bd. ix. S. 

 106). Masini ("Sui centri motori cort. d. larynge," Napoli, 1888) got unilateral effects 

 from stimulation and ablation of Krause's centre, but his results have not been confirmed 

 by others. Ferrier occasionally found that in the dog stimulation at the point marked 9 in 

 Fig. 332 produced a loud bark, West Ridinq Lun. Asyl. Rr,p., London, 1873. Duret, Compt. 

 rend. Soc. de bioL, Paris, 1877, and "Etudes expe'r., etc.," Paris, 1878, found loss of 

 the bark to result from bilateral extirpation of the region 9 of Ferrier (see Fig. 332), while 

 mechanical excitation by pressure upon this region caused a succession of barks. In 

 connection with this, it is interesting to note that the bark of the dog has been acquired 

 as the result of domestication, and may be said to answer in a measure to "speech" in 

 man. 



7 Everett Flood, Brit. Med. Journ., London, 1894, vol. ii. p. 189. 



