310 S. Simpson, 



liai sensation, more especially witli regard to li emiopia, was also 

 examined. The animal was weighed at regular intervals to test the 

 effect of the operation on its general condition. The results of each 

 examination were recorded on a chart at the time the observations 

 iuere made; these charts were preserved along with the notes of the 

 case, and from them the symptoms are briefly summarised. 



Results of Experiments, — Physiological and Anatomical. Gat. 



Lesion — Naked-eye Apijearances. When the animal was killed 

 and the brain removed, and again after it had been partially harden- 

 ed in Mliller's fluid or formol, the position and extent of the lesion 

 were noted and photographs of the brain were taken. On slicing 

 away the anterior portion of the hemisphere, the gross effects of the 

 lesion could be seen in most of the cases as a reddish-brown patch 

 due to blood extravasation, and the depth to which this extended in 

 the corona radiata could easily be made out. In every case the dura 

 mater was found to be adherent to the surface of the cortex over the 

 sigmoid gyrus and to a greater or less extent of the anterior extre- 

 mities of the 1-*, 2'^'^^ and 'ò^^ convolutions on the left side. In one 

 case the mesial surface of the posterior limb of the sigmoid gyrus on 

 the right side was injured. On tracing the lesion backwards into the 

 corona radiata it was found, in two cases, to have involved the head 

 of the caudate uucleus to a slight extent, but in no case was any 

 injury done to the optic thalamus, and in none of the other fourteen 

 cases did the lesion extend as far as the caudate nucleus. 



Symptoms residtiny from Operation. These were found to vary 

 considerably in the different cases, more especially with regard to the 

 disturbances of sensation. In every case the production of the lesion 

 was followed l)y motor paralysis of tlie right limbs. This was (piickly 

 recovered from as regards the "associated movements" of walking, 

 iiiiiuiiig etc. Tlie animals Avere not examined, as a riUe, until tbe 

 second day after the operation when the eifects of the anaesthetic and 

 of tlie shock had comi)letely passed off, and tlien, when renuived from 

 the cage and allowed to walk about the room tliey stumbled or fell 

 towards the right side, and when made to jump down from a table 



