A STUDY IN MORBID AND NORMAL PHYSIOLOGY. 



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may fairly be attributed to the complete suspension of respiration; the tightly 

 contracted muscle allowing only sufficient artificial respiration to maintain life. It 

 must of course be remembered that it was essential not to injure the animal, and 

 that consequently artificial respiration waS" limited to external manipulation. After 

 respiration was re-established the bodily temperature b(>gan to rise. The hourly 

 rate of heat production at this time was 79.49-47 instead of 34.6575 — a remarkable 

 diiference. This experiment apparently confirms the results of medullary section, 

 showing that the inhibitory centre is situated at least as high up as the pons. 



The next experiment was continued longer, and gave results less readily ex- 

 plained than those just discussed. Immediately after the injection, as well as 

 later, the heat production was found to be much reduced. The autopsy showed a 

 complete destruction of the left cerebellar lobe and peduncle, as well as of the upper 

 portion of the pons. So extensive a lesion may well be expected to cause vaso- 

 motor disturbance, and it has been abundantly proven by the effects of section of 

 the cord that the action of the higher heat-centre is dominated by the vaso-motor 

 system ; indeed the effects upon heat dissipation and production, in the experiment, 

 were exactly such as follow section of the cord. The production of vaso-motor 

 palsy seems to me the most plausible explanation of the phenomena noticed. A 

 possible explanation is also afforded by the supposition that the heat-controlling 

 fibres or centres in the pons escaped, the pons having in truth been only partially 

 destroyed. The difficulty of exactly locating the lesion, multiplied as it is by the 

 fact that two injections are of necessity required in the upper brain (one for each 

 side), has deterred me from making many of these injection experiments ; the 

 following are all that I have performed: — 



Experiment 74. 



4 p. M.— Dog killed. Left corpus striatum the only part of the brain injured— it totally destroyed 



