520 PHYSIOLOGY. 



cuts out the thermogenic and thermo-inhibitory centers in front of 

 the section and permits the thermic apparatus behind the section to 

 elevate the temperature. That a greater rise of temperature should 

 ensue after pontal than after crural section is quite in accord with 

 the well-known fact that successive sections from before backward 

 cause a greater activity of the spinal-cord centers behind the section, 

 and also of the trophic centers. 



Fig. 183 Cortex of Cat's Brain. 



g, Cruciate thermo-inhibitory center of Eulenberg and Landois. 8, Sylvian 

 thermo-inhibitory center of Ott. 



Now, I have shown that after the intravenous injection of beta- 

 tetrahydronaphthylamin in the normal animal a great rise of tem- 

 perature ensues. But after section through the crura cerebri this 

 drug is powerless to raise the temperature. A needle-point thrust 

 into the pons or crura causes a fugitive rise, and a feeble one. But if 

 the needle goes into the corpora striata or tuber cinereum there is a 

 quite permanent and considerable elevation of temperature. To as- 

 sume that a different kind of thermogenic center exists in the pons is 

 begging the question. 



