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HANDBOOK OF PHYSIOLOGY. 



upper lip and depression of lower; of 9, opening of mouth and protru. 

 sion of tongue; of 10, retraction of tongue; of 11, action of platysma; 

 of 12, elevation of eyebrows and eyelids, dilatation of pupils, and turn- 

 ing head to opposite side; of 13, eyes directed to opposite side and up 

 wards, with usually contraction of the pupils; of 13', similar action, but 

 eyes usually directed downwards; of 14, retraction of opposite ear, head 

 turns to the opposite side, the eyes widely opened, and pupils dilated; 

 of 15, stimulation of this region, which corresponds to the tip of the un- 

 cinate convolution, causes torsion of the lip and nostril of the same side. 

 It is thus seen that the motor areas chiefly correspond with the as- 

 cending frontal and ascending parietal convolutions, and that the move- 

 ments of the leg are represented at the upper part of these convolutions, 



FIGS. 356 and 357. Diagram of monkey's brain to show the effects of electric stimulation of cer- 

 tain spots. (According to Ferrier.) 



then follow from above downwards the centres for the arms, the face, 

 the lips, and the tongue. 



According to the further researches of Schafer and Horsley, electrical 

 stimulation of the marginal convolution internally at the parts corre- 

 sponding with the ascending frontal and parietal convolutions, from 

 before backwards, produces movements of the arm, of the trunk, and 

 of the leg. 



A good deal of doubt was thrown upon the experiments of Terrier 

 by Goltz and other observers, from the results of excising the so-called 

 motor areas of the dog's brain. It was found that the part might be 

 sliced away or washed away with a stream of water, but that no perma- 



