641 



paralysed muscle. Apparently there has been physiological or ana- 

 tomical division of the nerve supply (see Sherren), (6). 



The same accident occurs not infrequently in horses and cattle, 

 and as the question of prognosis is materially affected by the pre- 

 sence or absence of spinal accessory supply, it seemed advisable to 

 study what literature is available on the subject. 



In a horse at present under ob- 

 servation, apparent complete recovery 

 ultimately resulted from the injury. 

 Six weeks is the outside limit given 

 by veterinary surgeons for recovery 

 from the accident. In the horse men- 

 tioned, however, there is ataxia of the 

 shoulder. As long as the animal is 

 driven in a straight line, its recovery 

 seems to be complete. As soon as it 

 attempts to turn, the ataxia appears, 

 and the animal may even fall to the 

 ground. The condition of the animal 

 seemed to me to be explained by the 

 fact that the spinal accessory which 

 conveys the motor supply to the muscle 

 has remained uninjured, as our ex- 

 periments have led us to anticipate. 

 The cervical nerves are, however, per- 

 manently damaged. The ataxia deve- 

 lops in consequence of the injury to 

 the afferent nerve-supply. The horse 

 in question shows much less ataxia if 

 it be allowed to turn slowly. 



As the giraffe is unable to move 

 quickly, I have not seen ataxia well 

 marked in the shoulder, though I have 

 watched for it carefully. Certain ex- 

 periments performed by Chauveatj 

 and by Lesbre and Maignon throw much light on this point. 



M. Chauveatj found that excitation of the cervical nerves to the 

 sterno-cephalicus produced contraction of that muscle, but the con- 

 traction did not occur if after section of the cervical nerve the 



41 



Condition of giraffe on May 18 th, 

 1912. (3 months after the accident.) 



Note the dropping of the left 

 shoulder and wasting of the left 

 brachiocephalic muscle. 



The flexion of the radio-carpal 

 joint is compensatory. 



The animal is not yet able to 

 plant its hoof firmly on the ground. 



Anat. Anz. Bd. 41. Aufsätze. 



