Analyse der Folgezustände einseitiger Labyrinthexstirpation etc. 225 



touched the ground), but the turning of the head still continues. Now 

 at once the animal subverts the hind-part of the body and also turns 

 it to the operated side. 



Doing so — the animal has then rolled round its longitudinal 

 axis in the direction of the operated side , and it is not rare to see 

 this movement repeated several tiraes. 



Every revolution is accomplished in two tempos, or rather it may 

 be decomposed into two semi-revolutions. By the first of these, head, 

 and neck are turned towards the operated side, the opposite Shoulder 

 is turned upward , subsequently the crossed fore-leg is extended and 

 abduced and turned upward also. The turning of head and neck 

 goes on until a position is attained, that does not allow of maintaining 

 the hind-part of the body in its original position towards the distorted 

 fore-part. This first part of the revolution apparently does not 

 depend on the will of the animal, but seems rather to be involuntary, 

 as an inevitable automatisme. Head and neck (and subsequently the 

 opposite foreleg is rised) are forced in their position to the side of 

 the Operation, But the second part of the revolution movement has 

 another origine. It is irapossible for the animal with its fore-part so 

 turned, to maintain the original position of the hind-part, and it seems, 

 that this movement depends from the animal's willing. Voluntarily 

 the hind-part is thrown towards the operated side . . . 



. . . For the extremities on the operated side remain inactive 

 during the revolution round the longitudinal axis. They are lax . . . 



. . . We will therefore commence with the roUing of the body 

 around its longitudinal axis in the direction of the operated side. 



I have demonstrated already , that neck and head , shortly after 

 the Operation, have been turned round in such a manner that for a 

 rormal animal it becomes impossible to remain seated on the ground 

 with its lower extremities, its fore-part having assumed a forced 

 attitude, exceeding a certain degree. All the more so, because of the 

 fact that this position does not retain permanently the same intensity, 

 but is at intervalls suddenly intensified. 



If the rabbit, like the pigeon, did possess a long and easily 

 movable neck, that could be laid down on the ground and find a 

 Support there , whilst the head was being turned upward , then the 

 turning might perhaps , at it is in pigeons , still be checked , and the 

 turning of the head only might occur until 270 ^ or even 360 *'. 



Now this is impossible in rabbits. Therefore the animals roll. 

 This rolling of the body round its longitudinal axis is therefore always 

 accomplished in two tempos. The first automatic tempo of the rolling 

 is the same as it is observed in pigeons. The head is thrown vigor- 

 ously towards the operated side , turned so far , that its dorsal 

 cranial plane touches the ground. The head then turns 180". As is 

 described already, at this moment the upper extremity of the opposite 

 side, drawn by the movement of head and neck, is extended and 

 abduced as far as possible from the body, and by scratching the ground 

 tries to prevent a further turning of the head. But if once the head 

 has been turned further, if its dorsal plane touches the ground, if 

 the turning surpasses 180", the aid of the upper extremity becomes 



