18 



3d. That after a complete transverse section of the spinal 

 cord, the functions of that organ may be entirely restored. 



As to the nerves, the experiments of Fontana, Haighton, 

 Tiedemann, Flourens, Steinrueck, and many others, have de- 

 monstrated the possibility of reunion of the two extremities of a 

 cut nerve. But, in most, if not in all these experiments, the re- 

 turn of sensibility and of voluntary movements have not been 

 complete. The following fact is, consequently, very important, 

 because it proves the possibility of a complete reappearance of the 

 lost faculties after the entire division of a nerve.* 



A guinea-pig, on which the sciatic nerve had been cut across, 

 exhibited indications of a return of sensibility a month after the 

 operation. Two months afterwards the sensibility was increased, 

 but was still much inferior to that of the sound limb. The mus- 

 cles then were beginning to contract under the influence of the 

 will. Six months after the section, the animal could evidently 

 move its legs and toes voluntarily ; the sensibility then was almost 

 entirely recovered. At the end of about eleven months, the 

 sensibility and all the voluntary movements were apparently 

 alike in the two posterior limbs. The animal having been killed, 

 it was found by my friend Dr. Lebert and myself that, except 

 a slight union of muscular fibres with the nerve at the place 

 where it had been divided, the restoration of the original condi- 

 tion was so complete that no indication of the division could be 

 discovered, either with the naked eye or with the microscope. I 

 had seen the usual swelling of the nerve at the point of reunion 

 about the sixth month after the operation, but at the time of the 

 last examination it had disappeared. 



V. ON TURNING AND ROLLING AS PHENOMENA PRODUCED BY 

 INJURIES OF THE NERVOUS SYSTEM. 



Pourfour du Petit and Me'he'e de la Touche were the first expe- 

 rimenters who witnessed turning produced by an injury of the 

 nervous centres. But the first valuable researches on this phe- 

 nomenon were made by Magendie and Flourens. 



The parts of the cerebro-spinal centre which can be injured 

 without producing turning, are : the cerebral hemispheres, the 



*See Gaz. Med. de Paris, 1849, t. iv. p. 880. 



