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Ley ton and Sherrington 



weaker stimuli in any one of the three animals than in the others. On 

 the contrary, the evidence was that the threshold of excitability was closely 

 similar for all three, 



VII. Influence of Local Cold and Warmth applied to the Scalp 

 ON THE Local Temperature of the Cortex underneath. 



Large chimpanzee, anfesthetised and trephined in lateral frontal region 

 of left side ; the thickness of skull in this place was S'S mm. as measured 

 on the edge of the button of bone removed. The trephine hole was 

 slightly enlarged antero-posteriorly, the dura opened, and the bulb and 

 stem of a slightly curved and flattened small thermometer was introduced, 

 and gradually shifted under the dura for 4-5 cm. in a posterior direction. 

 The bulb thus lay under dura and bone about 4*5 cm. behind the hole in 

 the skull and in a postero-lateral direction from it. The issuing stem of 

 the thermometer, wrapped in dry cotton-wool for its part next the lips of 

 the wound, was readable. The room temperature was 27° C. After the 

 intracranial thermometer had been giving steady readings for a time an 

 ice-bag was applied to the scalp in the left parietal region, approximately 

 over the seat of the bulb of the thermometer inside. The diameter of 

 application of the bag was 9 cm. Its edge did not come quite close to the 

 edge of the skin wound and the emergent thermometer. 



The followino- illustrates the observations obtained. 



