Secondary Degeneration followinfi; Unilateral Tiesions etc. 309 



limb. To test the grasping power (in monkeys) a small stick, or pre- 

 ferably the observer's finger, was held out to the animal, and its power 

 of hanging on to any object which it had seized, such as the wire 

 netting- of the cage, was also noted. 



In testing general sensibility the part to be examined was touch- 

 ed or stroked lightly (not pricked) with a needle at the end of a 

 long stick, while the attention of the animal was attracted l)y an- 

 other person, so that it might not see that it was being touched. If 

 tactile sensation is not impaired the animal looks round and with- 

 draws the limb, or indicates by some gesture that it feels the touch. 

 To test whether pain was felt it was pricked with the needle. The 

 plan generally adopted was to test for pain first, for after an animal 

 has been pricked once or twice, it responds more readily to a simple 

 touch probably from apprehension of a prick. The "clip-test" intro- 

 duced by Schiff, and relied on by Mott [4\ and others, was also em- 

 ployed, but as pointed out by Schäfer [5], it is misleading, and want 

 of response to this test indicates motor rather than sensory paralysis. 

 If a steel clip is applied to the skin while the animal does not see 

 what is being done, an attempt will be made instantly to remove it 

 from a sound limb, but if the limb is paralysed no notice may be 

 taken of it. Often it was found that an animal would respond to a 

 simple touch, while it would take no notice of a clip. 



In examining as to whether the sensations of heat and cold were 

 affected, the animal was suspended in a sling-jacket, and when per- 

 fectly quiet, a vessel containing hot or cold water was brought up 

 underneath it until the fingers or toes dipped into the water. If 

 sensation was present the limb was withdrawn, or if there was vol- 

 untary paralysis of that limb the animal indicated by struggling or 

 otherwise that it felt the hot or cold water. It was found in every 

 case that the animal responded when hot water was applied to the foot 

 or hand, but on the paralysed side the sensation was often delayed 

 for a surprisingly long time, — in some cases as long at twenty se- 

 conds. The knee-jerks were tested in the usual way. The temperature 

 of the rectum, axilla, anticubital fossa, groin and popliteal space was 

 taken from time to time, and the condition of the pupils and of vis- 



