84 PHYSIOLOGY CHAP. 



white matter round the corpora striata or the cerebellum. He, 

 however, admits that injuries to the peduncles of the brain cause 

 a rapid rise in temperature. It also follows from the records of 

 his experiments that injury of the convolutions of the brain may 

 cause marked disturbances in the regulation of temperature in 

 one such case he recorded a temperature of 41 -3. His opinion 

 that the corpus striatum is the, true thermogenic organ of homoio- 

 thermic animals does not appear to me tenable. 



At the same time (1890) I. Ott announced as the result of his 

 researches upon the brain that there are a number of cerebral heat 

 centres : one in front of and under the lenticular nucleus, a second 

 in the convexity of the caudate nucleus, a third in the lamina 

 cornea, a fourth in the front and inner part of the optic thalamus, 

 a fifth in the Rolandic area of the cerebral cortex, and a sixth in 

 the cortex in the Silvian fissure. 



If, however, there are six cerebral heat centres in the rabbit 

 and the cat twelve, indeed, since they are symmetrical it is 

 impossible, when we come to think it over, to localise them 

 exactly, and we are thus led to the conclusion formed by 

 Richet that all parts of the brain, as the result of lesions more 

 or less deep and irritating, can produce a more or less definite 

 hyperthermia. 



Richet cauterised superficially the cerebral cortex of dogs 

 which were kept motionless, and found that the temperature of 

 the rectum rose 0'5 and even 0'75. F. Tangl (1895) found that 

 a puncture in the front part of the optic thalamus of the horse 

 made the temperature rise in one case to 40 '4, and in another to 

 40 '8 ; in two other horses there was no rise of temperature when 

 the puncture had not touched the optic thalamus. In many 

 cases of traumatism and cerebral tumours, surgeons have observed 

 hyperthermia uncomplicated by sepsis or convulsions. 



In a case of fracture of the skull with haemorrhage compress- 

 ing the temporo-occipital region, Broca saw the temperature rise 

 3 in a few hours ; in another case the temperature rose 5 in six 

 hours and a half. After ablation of an angioma of the brain, the 

 temperature rose to 42*1 ; in a case of cysts to 41'8 ; in one of 

 tumour at the base of the skull to 41 -9 ; and in one of parieto- 

 occipital tumour to 42. 



When injuries causing irritation of the brain do not cause 

 any marked change in the normal temperature, the conclusion 

 must not at once be drawn that they have caused no increase 

 in the organic processes of combustion, since the increase in 

 the heat produced may be balanced by an equal increase in the 

 heat lost. 



The very definite records of hyperthermia following different 

 injuries to the brain, show that the thermogenic functions of the 

 brain are no less marked in man than in the higher animals in 



