582 PHYSIOLOGY CHAP. 



muscular sensibility persists for a few hours after the operation, 

 but then passes off gradually, and almost entirely disappears 

 after a few days, so that it is difficult without careful investigation 

 to distinguish between the operated and the intact animal. 



Evidence for these facts is given by Carville and Duret, 

 Albertoni and Michieli, Lussana and Lemoigne, and Luciani and 

 Tamburini. 



The symptoms described by Goltz after complete extirpation 

 of the whole anterior half of the dog's left hemisphere, which 

 certainly included more than the whole of the excitable area on 

 that side, are more characteristic and detailed. At first there 

 was complete motor and almost complete sensory hemiplegia of 

 the whole of the right side. After a few days the animal improved 

 to the extent of walking without falling, but showed a tendency to 

 turn to the right, and weakness and uncertainty in the movements 

 of the limbs of that side. If placed on a table the animal fell 

 easily, and then beat the air with its right limbs, as already 

 noted by Hitzig. In gnawing bones, pieces readily fall out of 

 the right side of the mouth, as Schiff had already observed. If 

 the animal had been trained to give its right paw when invited, 

 before the operation, it would now only give the left. 



According to Goltz the sensory disorders are even more 

 important than the motor. The disturbance of muscular sense, 

 as recognised by Hitzig, is unmistakable, but the disturbance of 

 tactile sensibility is 110 less striking, although the power of 

 recognising contacts on the right half of the body is not entirely 

 lost, as was erroneously assumed by Schiff. 



JSfo less important is the description given by Goltz of the 

 effects of bilateral extirpation of the entire anterior half of the 

 hemispheres to about 7 mm. in front of the chiasma. On 

 recovering consciousness a few hours after the operation the 

 animal makes futile attempts to stand. It cannot swallow or 

 lap milk, but has to be artificially fed for several weeks. The 

 power of standing and walking, in a very shaky way at lirst and 

 afterwards more and more steadily, is regained before the power 

 of feeding itself. About two months after the operation the defect 

 phenomena become almost stationary. 



Although the animal has recovered its power of standing 

 upright, walking, running, jumping, these actions are awkward 

 and imperfect. The hind-legs drag, and it slips easily on a smooth 

 floor, but can rise alone. If the bilateral lesion is tolerably sym- 

 metrical, it is able to walk in a straight line, or to right or left, 

 according to its needs ; but if the lesion is very unsymmetrical, it 

 leans to the side most injured, although it may turn to the opposite 

 side. There is no muscular paralysis, and sensibility is not lost in 

 any part of the body, but there is a marked hyperaesthesia of the 

 skin, recalling that described by Brown-Sequard after spinal liemi- 



