PARALYSIS OF THE GREAT SCIATIC NERVE 167 



was moved, and weight was placed on it in the usual way, the left leg was 

 carried close to the middle line of the body (adducted), and was placed 

 too far in advance and too near the right side, causing the animal to tall 

 towards the right side ; the body was only saved from coming to the 

 ground by a rapid spring with the left foot." The muscles supplied by the 

 anterior tibial nerve and its continuations — -namely, the flexor metatarsi, 

 extensor pedis, and the peroneus — being unable to perform their ordinary 

 functions, the stifle and hock were in a condition of excessive extension, and 

 the limb appeared much longer than the corresponding limb ot the other 

 side. Owing to the inactivity of the extensor pedis and peroneus muscles, 

 the animal was unable to extend the fetlock and interphalangeal joints, so 

 that these remained excessively flexed, the foot resting with the anterior 

 portion of the wall on the ground, and the sole being directed backwards. 

 The leg was dragged forward only by the action of the crural muscles, and, 

 owing to the loss of control over the joints below the stifle, the action was 

 most insecure, and the movements described above recurred at every step. 

 The excessive flexion of the lower joints caused the animal at times to 

 walk even on the front of the fetlock joint. When assistance was ren- 

 dered in extending the fetlock and lower joints by means of a rope passed 

 round the fetlock, the animal walked with perfect ease, but the difficulties 

 reappeared immediately such assistance was withdrawn. 



At first no anatomical changes in the limb were noted, neither were 

 there evidences of pain, but inability of the muscles in front of the 

 tibia was detected by palpation during movement. That the areas 

 supplied by the anterior crural and gluteal nerves were not affected 

 was evident from the fact that these parts reacted to stimuli, but there 

 was no such reaction in the lower portion of the thigh or phalangeal 

 region. 



"Three weeks after the first appearance of lameness an inflammatory 

 swelling appeared between the anus and tuber ischii, showed fluctuation, 

 and on incision discharged about two quarts of very offensive, lumpy pus. 

 After enlarging the orifice the hand could be introduced into an exten- 



