30 THE TONER LECTURES. 



ever may have been the cause of the primary fall, the fact that 

 the subsequent elevation of temperature was independent of the 

 external heat shows that the primary fall was due to some tem- 

 porary cause, and that the experiment really corroborated the 

 others. 



J. Bruck and A. Giinter {PJiuger^s Archiv, Bd. iii. p. 579) have 

 also experimented upon the effect on the temperature of section 

 of the medulla oblongata at the border of the pons. They used 

 rabbits, and operated without opening the skull. Out of seven 

 f operations they found that once the tempei'ature rose enor- 

 mously after the section, once it rose very decidedly (1.1^ C.) 

 and in foiir cases fell continuously. The reason of the varying 

 result seems to me to be found in the small size of the animal 

 used. It must be remembered, that, if the vaso-motor centre be 

 injured directly or indirectly in the operation, a fall of tempe- 

 rature must occur precisely as if the spine were cut lower 

 down, and, as Bruck and Gunter did not bring the animals into 

 a warm place, such fall of temperature would necessarily be 

 permanent. No effort was made by the observers to determine 

 whether or not the vaso-motor nervous system was affected ; and, 

 as, in the rabbit (speaking from memory), the distance between 

 the point assigned by Owsjannikow as the vaso-motor centre 

 and the border of the pons cannot be more than a tenth 

 of an inch, I think it is a fair inference that the vaso-motor 

 centres were affected. No details of the experiments are given, 

 but the reporter says, that the " bad success of the operation 

 seemed to have its foundation in the too quick death of the 

 animal." Taking all these circumstances into consideration, I 

 do not think I can justly be accused of any desire for special 

 pleading when I come to the conclusion, that, whilst the suc- 

 cessful experiments of Bruck and Giinter confirm those already 

 detailed in this paper, the failure in other cases of the tempe- 

 rature to rise in no wise invalidates the conclusions to be 



