494 A MANUAL OF VETERINARY PHYSIOLOGY 



observed to walk lame, holding the injured foot off the ground. It 

 is possible to urge that pain was felt, as some portions of the brain- 

 stem had been left intact ; but Sherrington's remarkable experi- 

 ment on the decapitated cat disposes of this.* A cat so treated 

 cannot stand, but it can perform stepping movements with its 

 limbs. ' If, as the preparation lies on its side, one hind-foot be 

 forcibly pinched, this limb is flexed . . . and the other limbs at 

 once begin rapid, co-ordinated stepping movements. The 

 injured foot is held up out of harm's way, and the other legs run 

 away.'f 



Removal of an anterior lobe of the cerebrum in the dog leads 

 to unilateral motor and sensory paralysis ; the motor paralysis is 

 recovered from, but the loss of muscle sense remains. Removal 

 of the posterior lobes of the cerebrum leads to blindness ; there 

 is no paralysis, sensory or motor ; the dog remains obedient, but 

 sluggish. Sherrington cut the brain off from the heart and viscera 

 in the dog by division of the cord in the lower cervical region. 

 The animal showed joy, anger, fear, and sorrow. Nothing would 

 induce it to eat dog's flesh, but in this case the olfactory and 

 gustatory paths were still open ; in Goltz's dog they had been 

 removed. That ' dog will not eat dog ' is a very old maxim, but 

 travellers in the Arctic have recorded the fact that they will do 

 so as occurring under stress. Nevertheless, it is remarkable that 

 both the idiot created by Goltz, and the dog furnished by 

 Sherrington, with no knowledge of its stomach, should refuse 

 to eat their own kind. In this matter they furnish a far nicer 

 discrimination than man. 



Observations on man, begun in the Franco-German War and 

 continued on animals, have demonstrated that the cortex, which it 

 must now be made clear is the elaborating part of the cerebrum — 

 as distinct from the white or connecting matter — contains an area 

 which controls the voluntary muscles of the body, and is known 

 as the motor area. There is another area connected with body 

 sensibility, such as muscle sense, touch, pressure, and temperature. 

 This is known as the sensory area, and comprises not only the 

 body senses above mentioned, but the special senses of sight, 

 hearing, taste, and smell. The position of these is known in the 

 sheep, dog, monkey, and man with considerable accuracy, so that 

 maps of the hemispheres have been drawn up indicating the 



* Brain, part cxxix., vol. xxxiii., 1910. 



f These astonishing results show that lameness may be purely reflex in 

 origin. The question of the fitness or unfitness of chronically lame cases 

 to perform work will in time have to be considered afresh. The above 

 observations show with what justice the veterinary profession, as the 

 result of pure observation, has urged in a court of law, though generally 

 without success, that an animal suffering from lameness is not necessarily 

 suffering pain. 



