Chapter I. 



The removal of the rabbit-labyrinth. The section 

 of the N. oclavns and of its prolongation in the central 



nerve-system. The disturbances 

 of motion following on these operations. 



I. A few tecJtnical remarks on the removal of the labyrinth in rabbits. 



Before trying to remove the labyrinth of rabbits, it is advisable 

 to learn this operation on pigeons, all the while following strictly 

 the technical directions, described with so minute a preciseness 

 by EWALD, without neglecting any of the details given by him. 



If the removal of the labyrinth is performed with the purpose 

 of investigating, after a more or less prolonged duration of life of 

 the animal , the secondary degenerations and atrophies in the central 

 nerve-system by means of the methods of MARCHI or GUDDEN, it 

 is of the utmost importance to take care that no accessory lesion 

 may occur. 



For the same reason, .with pigeons likewise as with rabbits, 

 the most careful antisepsis in the preliminary stage of the operation 

 and the strictest asepsis during its course are necessary , and some 

 subordinate parts of it ought to be executed with great circum- 

 spection. On the one hand, it is of absolute necessity to avoid any 

 bleeding during the operation. On the other hand the method of 

 the cauterizing the blood-sinus offers a danger , even when following 

 strictly the rules prescribed by EWALD. This danger is that the 

 heat, passing through the bone, may have scorched at a distance 

 the surface of the cerebellum and may thus have created the origin 

 of a secundary degeneration. And a pigeon, having a superficial 

 lesion of the cerebellum even though this may not be betrayed 



