INJURIES OF THE NERVOUS SYSTEM. 711 



that this ganglionic mass is an independent centre of sensation and of motor 

 power ; but they do not afford any clear information as to its special attributes. 

 He states, however, that convulsive movements are excited by irritating it, and 

 especially by the transmission of an electric current through its substance. 

 These movements, however, according to the testimony of Dr. Todd, appear to 

 be of a different character from those which are excited by the application of 

 the same stimulus to the Spinal Cord and Medulla Oblongata; for he states 

 that, whilst the convulsions excited by the transmission of the current of the 

 magneto-electric machine through the parts just named are tetanic, the muscles 

 being thrown into a state of fixed contraction those which ensue when the 

 current is transmitted through the region of the Mesocephale and Corpora 

 Quadri gemma are epileptic, being combined movements of alternate contraction 

 and relaxation, flexion and extension, affecting the muscles of all the limbs, of 

 the trunk, and of the eyes, which roll about just as in epilepsy. 1 



[Dr. Brown-Sequard, whose experimental researches have been frequently 

 quoted, has published the following resume of the phenomena produced by in- 

 juries of the nervous system. 3 



Pourfour du Petit and Mehee de la Touche were the first experimenters who 

 witnessed turning produced by an injury of the nervous centres. But the first 

 valuable researches on this phenomenon were made by Magendie and Flourens. 



The parts of the cerebro-spinal centre which may be injured without produc- 

 ing turning, are : the cerebral hemispheres, the cerebellum, the corpora striata, 

 the corpus callosum, the spinal marrow, and the olfactive and optic nerves. 3 In- 

 juries of all the other parts of the cerebro-spinal centres may produce turning 

 or rolling. 



These circulatory or rotatory movements take place sometimes on the same 

 side of the body, and sometimes on the side opposite to that portion of the en- 

 cephalon which has been injured. 



A puncture of one of the following parts produces turning or rolling on the 

 injured side : 



1. The anterior extremity of the thalami optici, according to Schiff. 



2. The crura cerebri, according to Magendie. 



3. The bi-, or quadrigeminal tubercles, according to Flourens. 



4. The pons Varolii. 



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



6. The auditive nerve, according to Brown-Sequard. 



7. The medulla oblongata at the point of insertion of the facial nerve, accord- 

 ing to the experiments of Brown-Sequard, in common with Dr. Martin-Magron. 



8. The medulla oblongata outside of the anterior pyramids, according to 

 Magendie. 



9. A great part of the posterior face of the medulla oblongata, according to 

 Brown-Sequard. 



The parts of the encephalon which produce turning or rolling on the opposite 

 side are : 



1 . The posterior extremity of the thalami optici, according to Schiff. 



2. The crura cerebri, according to Lafargue. 



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



4. A small part of the medulla oblongata before the nib of the calamus scrip- 



1 Lumleian Lectures "On the Pathology and Treatment of Convulsive Diseases," in 

 "Medical Gazette," May 11, 1849. 



2 ["Phil. Med. Examiner," August 1852.] 



3 [The three nerves of the superior senses, the olfactive, the optic, and the auditive, are 

 considered, by the author of the article here quoted, as a part of the nervous centres. ED.] 



