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cerebellum, the corpora striata, the corpus callosum, the spinal 

 marrow and the olfactive and optic nerves.* All the other parts 

 of the cerebro-spinal centres are able to produce turning or roll- 

 ing. 



These circulatory or rotatory movements take place sometimes 

 on the same side, and sometimes on the side of the body opposite 

 to that of the encephalon which has been injured. 



A puncture of one of the following parts produces turning or 

 rolling on the injured side : 



1st. The anterior extremity of the thalami optici, according 

 to Schiff. 



2d. The crura cerebri, according to Magendie. 



3d. The bi, or quadri-geminal tubercles, according to Flourens. 



4th. The pons varolii. 



5th. The posterior part of the processus cerebelli ad pontem. 



6th. The auditive nerve, according to my own experiments. 



7th. The medulla oblongata at the point of insertion of the 

 facial nerve, according to my experiments in common with Dr. 

 Martin-Magron. 



8th. The medulla oblongata outside of the anterior pyramids, 

 according to Magendie. 



9th. A great part of the posterior face of the medulla ob- 

 longata, according to my experiments. 



The parts of the encephalon which produce turning or rolling 

 on the opposite side, are : 



1st. The posterior extremity of the thalami optici, according 

 to Schiff. 



2d. The crura cerebri, according to Lafargue. 



3d. The anterior part of the processus cerebelli ad pontem. 



4th. A small part of the medulla oblongata before the nib of 

 the calamus scriptorius and behind the corpora olivaria, accord- 

 ing to my experiments in common with Dr. Martin-Magron. 



Some of these two series of parts ordinarily produce turning 

 and the others rolling. But these two kinds of movements can 

 be produced by the puncture of a single part of the encephalon. 

 Rolling is nothing but the exaggeration of turning ; thus, after 



* I consider as a part of the nervous centres, the three nerves of the su- 

 perior senses : the olfactive, the optic and the auditive. 



