22 C. WINKLEll. THE CENTRAL COURSE 



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 (fig. A C). The turning of head 

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

 maintaining the hindpart of the body in its original position towards 

 the distorted forepart. 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 automatism. 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 (fig. 8 D E). It is impossible for the 

 animal with its fore-part so turned , to maintain the original position 

 of the hindpart , and it seems that this movement depends from the 

 animal's willing. Voluntarily the hindpart is thrown towards the ope- 

 rated side. 



In order to obtain a just impression of the position of the 

 fore-part of the body, the best way is to lift up the animal 

 by the skin of the back. It may then be seen how the animal, 

 hanging free in the air, only supported by the hand in its back, 

 assumes, in consequence of the turning of head and neck, a very 

 peculiar position, not easily to be described. 



When observing it from the ventral side , we see that the ope- 

 rated side of the head is pressed against the shoulder of the same 

 side , looking dorsal ward and caudal ward , whilst the now operated 

 cheek is looking frontal-ward and cranialward. 



This forced attitude of head and 'neck of the animal (even the 

 upper (anterior) part of the trunk participating in it) is originated 

 as suddenly as that of the eyes after the removal of the labyrinth. 



To the purpose of giving a more minute description of the 

 characteristic attitude of head and neck , it is advisable to draw 

 mentally the mid-dorsal and mid- ventral lines of the animal , and 

 to take as a starting-point the stand of the medial plane of the 

 body brought through both lines. 



The mid-dorsal line is running from the tail over the process! 

 spinosi of the chest-vertebrae (caudo-thoracic portion of this line), 

 over those of the neck-vertebrae (cervical portion of this line) towards 

 the occiput, and thence passing between the eyes, over sagittal 

 suture and dorsum nasi towards the middle of the uppeiiip (cra- 

 nial part of this line). 



The mid-ventral line goes from the middle of the underlip over 

 the chin towards the larynx (cranial part of the mid-ventral line), 

 thence it descends opposite the trachea to the manubrium sterni 



