756 



THE CEREBRAL CORTEX. 



simple lateral deviation. All the effects are strongest upon the mesial 

 surface, especially towards the anterior limit of the lobe ; it is here that 

 the focal point for the movements is located. 1 



The movements are usually accompanied by dilatation of the pupils, 

 but I have occasionally obtained, from stimulation on or near the 

 quadrate lobule, marked contraction of the pupils, such as is produced 

 when a strong light is thrown directly into the eye. Equal bilateral 

 excitation produces, as with the frontal areas (p. 740), fixation of the 



LE.FT RETINA 



RIGHT RE.TINA 



C C/p JTA u C 



CC/pitM- 



Fig. 346. — Diagram showing the probable relations between 

 the parts of the retinte and the visual area of the 

 cortex. 



visual axes, with an upward or downward inclination according as the 

 electrodes are placed on the lower or upper zones above described. 2 If 

 we assume that these various movements of the eyeballs are the result 

 or concomitants of subjective visual sensations set up by the excitation, 



1 Schafer, Brain, London, 1888, vol. xi. p. 1. These observations have been confirmed 

 in dogs by Ohregia (with Munk), Arch. f. Physiol., Leipzig, 1890 (see also H. Munk, 

 Sitzungsb. d. k. Akad. d. Wissensch., Berlin, 1890, S. 53, translated in Brain, London, 



1890, vol. xiii. p. 45), and in the cat and rabbit by Steiner, Arch. f. d. ges. Physiol., Bonn, 



1891, Bd. 1. S. 603 ; also in the monkey, by v. Bechterew, Neurol. Ocntralbl., Leipzig, 

 1897, S. 720, who affirms that similar movements of the eyes and pupils are obtainable 

 by stimulation of the parietal lobe. 



2 Mott and Schafer, Brain, London, 1890, vol. xiii. 



