A STUDY IN MO 11 j; ID AND N O U M A L T 11 Y S I O L O U Y. 139 

 Table II. — One Fir.st Convolution Involved. 



EcMAKK.S. 



Left llitzig's ik'sti'iiyL'd ; iilsu cor- 

 IJiis callosiim. 



The only wouiiil of liraiii was so far 

 back as scarcely to be in llitzig's 

 region. 



A great deal of lileediiig with brain- 

 clots all over base, may account 

 for different results. 



RE,M.\ItKS. 



In looking over these tables it will be seen that there are fourteen experiments 

 in which one or both of the first convolutions were injured immediately behind the 

 sulcus cruciatus, and six experiments in which other portions of the brain were 

 alone affected. In not one of the latter was there any increase of heat production 

 worthy of notice immed ately following the brain injury, whilst in thirteen of the 

 fourteen experiments, compromitting the so-called "Hitzig's region," there was a 

 decided increase in the yield of heat. In the exceptional experiment a large sinus 

 was wounded, and the blood clotting upon all parts of the brain must liavc greatly 

 disturbed all the results, affecting profoundly by pressure both the vaso-motor and 

 respiratory functions ; the exceptional result is therefore very well accounted for. 

 Of the thirteen consonant experiments, in seven there was one, and in six there 

 were both of the first convolutions injured. In the latter set, the increase of heat 

 production was, reading the experiments as they arc arranged in the table, 

 about 35, 74, 36, 27, 6o, and 47 per cent.; in the experiments in which only one 

 centre was injured, the increased production of heat was, reading as before, 

 but omitting the first experiment because no study was made after the operation 

 until the next day, 10, 22, 11, 15, 30, and 12 per cent. The average increase 

 in the heat production was therefore 47 per cent. Avhen both sides of the brain 

 were affected, and 17 per cent, when only one side was compromitted. When to 

 this relation is added the fact that in twenty experiments the results w(<re uni- 

 form, except in one instance in wliich the brain was deluged with blood from a 

 wounded sinus, it is difficult to resist believing that in the dog de-strncfiou^ of the 

 hrain region hnown as ilic first cerebral convolution iwsierior to and in the vicinitij of 

 tlie sulcus cruciatus is follovcd Inj an increase in Jicat prodiwtion. It may be noted 

 that in several of the experiments,, in wliich other portions of the brain tlnni Ilitzig's 

 region were destroyed, there was a very decided fall in the rate of heat production. 



