A STUDY IN MORBID AND NORMAL P n Y S I O L G T. 157 



sciatic nerve in the dog liad no demonstrable effect upon the lilood pressure of tlie 

 corresponding femoral vein. This method of investigating the matter under con- 

 sideration led to no result; this is, however, not of vital importance, for it seems 

 scarcely conceivable, that a vaso-motor centre, whose paralysis was followed by 

 dilatation of all the muscular arterioles and whose influence upon lieat production 

 should be as great as is required by the facts of the case, should not impress, in 

 any way, the arterial pressure, even after withdrawal of the influence of the 

 abdominal circulation. It seems to me about as ncnirly demonstrated as it can be 

 that the centre in the medulla dominates the vessels in every part of the body, and 

 consequently that the rise of the heat production following section of the medulla 

 is not due to an influence exerted upon the circulation, but directly upon the heat 

 making function. The theory that teaches the existence of a nerve centre in the 

 pons or in the brain above it, which by a direct action inhibits the production 

 of animal heat, seems therefore to be most in accord with all the evidence bearing 

 upon the matter, and I am myself disposed to adopt it as at least very probable. 



It is a matter of much interest to decide as to the location in man of the centres 

 which control the production of heat. I do not believe that it is right to apply 

 rigidly to man, rules of localizations discovered in tlie cerebral hemispheres of the 

 lower animals. The differentiation, anatomical and functional, is so much greater 

 in the human than in the canine brain, that diversity of anatomical localization is 

 very probable. In determining the seat of caloric inhibition in man a great diffi- 

 culty offers itself. No human calorimetrical observations have been made at all, 

 and if we judge from a rise of bodily temperature vaso-motor disturbance may be 

 readily mistaken for an increased heat production. It is jjossible, however, that 

 close observation of apoplectic and traumatic brain cases, aided by cautions reasoning, 

 may, in the future, enable us to trace out the course of the heat fibres, and rather 

 with the desire of giving an impulse to the observation of cases than with the ex- 

 pectation of deciding the question, a brief discussion of tlie present evidence is here 

 entered upon. 



Evidently the first point to direct attention to is in regard to the pons Varolii 

 and the optic thalamus. 



Bastian states that in apoplexy of the pons, if the life of the patient be prolonged, 

 " the temperatnre of both sides of the body steadily rises, till at the time of 

 death it may have attained 109° or even 110°." (Pantl//sis from Bmiu Disease, 

 p. 220.) He also asserts that after hemorrhage into the optic thalamus the para- 

 lyzed limb may be for many weeks or months " one and a half or even two degrees" 

 hotter than the sound limb. Limbs paralyzed by hemorrhage in the corpus stria- 

 tum, or its neighborhood, are said also to be slightly but temporarily hotter than 

 the sound limb. Upon wdiat or how many cases Dr. Bastian rests these general- 

 izations I do not know. Hemorrhage confined to the optic thalamus is rare. The 

 only case I have a inference to is that reported by Dr. Remy {BuU. Soc. de Anat., 

 Paris, 1875, 3 ser. x. p. 158). In this the original attack came on early in 

 October, 1874, but the snbjcct did not come under observation until the ninth of 

 November. The temperatures as taken in this case were — 



