1891.] which follow total extirpation of the fore-brain. 157 



These questions I do not propose to answer in the present paper, 

 which is but of the nature of a preliminary communication. 

 I can here only state the results of certain first steps towards a 

 resolution of the problems, and note the variations in the tempe- 

 rature of the body, as measured by the thermometer, during the 

 days immediately following upon the removal of the cerebrum. 



For these experiments I made use of the fowl. Mammals 

 were out of the question for any prolonged observations, inasmuch 

 as they cease to manifest any vitality whatsoever in the course 

 of but a few hours after the hemispheres have been extirpated ; 

 and I employed the fowl rather than the pigeon (which other- 

 wise has many advantages) because with the former it is the 

 more easy under ordinary conditions to induce experimental fever. 

 In the a-volitional non-sentient state which follows removal 

 of the cerebral hemispheres the fowl, it is well known, may con- 

 tinue for weeks, and it may be months. When however in 

 addition to the hemispheres the optic lobes are to a greater or 

 less extent extirpated, as was purposely the case in my ex- 

 periments, then this state, it would seem, can last for a much 

 shorter time, the bodily functions ceasing in from one to ten 

 days according to the amount of obliteration of these organs 

 that has been practised. Hence in these experiments it cannot 

 be said that the stage of ' shock ' following the operation has 

 definitely been passed : it is impossible to declare that the 

 variations in temperature which I am about to describe are not 

 largely due to the highly irritable condition of the rest of the 

 nervous system brought about by operative interference and re- 

 moval of the higher centres. 



Kept at an equable and moderate external temperature the 

 ordinary fowl exhibits during the day a variation in the body 

 temperature of at most 0*75° C, the mean temperature of well- 

 fed fowls as measured in the rectum being — in winter — about 

 42 - 3° C. (108° F.). But after extirpation of the hemispheres and 

 optic lobes — the latter wholly or partially — the temperature 

 variations became very wide, passing from below 35° to above 

 45° C, and it was a matter of extreme difficulty to prevent, 

 even for a few hours, well-marked ascents or descents of the 

 temperature. Removal, therefore, of so large a portion of the 

 brain had thoroughly disturbed the balance between the thermo- 

 genic and thermolytic powers of the organism. 



So great had been the disturbance that now the fowls reacted 

 to changes in the external temperature much in the same way 

 as do cold-blooded animals. Placed in a room whose temperature 

 was 22° C. (71 "6° F.), and covered carefully with cotton wool 

 the rectal temperature rose rapidly until in those instances in 

 which the rise was unchecked it reached the height of 44'5° C. 



