M KKVKK. 



ArrKU Skction. 



0.00338 X ■ 7 JI3 grnmme* = CO, leaving box. 



0.00175 X l-^U ^ 2.136 graiiiuivA ss CO, voU-riiig box. 



CO,prod>teed in an hour 7.61C3 {grammes. 



In Studying these ex|H'riiiu'nts it will be seen thut in each there was a very 

 decided increase in the throwing' oil" of heat hy the animal after divibiuu of 

 the cord. In Experiment 20 llie cord was cut in its middle region between the 

 second and third dorsal vertebne, above the origin of the great splanchnic nerves; 

 there was, therefore, vaso-niotor paralysis affecting almost the entire trunk and 

 the lower extremities. Tlie hourly increase of heat loss was enormous, equalling 

 one-third of the original anioiint. In Experiment 28 the cord Was cut in very 

 nearly the same place as in the preceding experiment, but the increa.se of heat dis- 

 sipation, although decidt'd, was not nearly so great. In Experiment 30 the section 

 was practised one vertebra higher up, but the increase of heat liissipation was 

 comparatively very slight, not amounting to more than l:{ percent, of the original. 

 Tin- animal wa.s, however, a pup, and in this fa<t probably lii-s the reason of the 

 comparative poverty of increase. In Experiment ;U the cord was cut in the np|HT 

 dorsal region, above the origin of the splaiichnics, and the increase of heat dissi- 

 pation amounted to nearly 30 per cent. 



In the remaining experiments of the series the cord was divided in the cervical 

 region. In Experiment '25 the division was between the fifth and sixth cervical 

 Vertebra.', and the increase of lu-ut dissipation amounted to over oO per cent, of the 

 original yield. In Experiment 27 the section was practised slightly higher, and 

 although respiration was profoundly affected, the rate of heat dissipation rose 

 over 30 per cent. In Experiment 29 the cord was cut about the same place, at 

 the sixth cervical vert(>bra, and the incrciise of heat evolution was over oO percent 

 althougli ronsideral)le l)lood was lost. 



The experiments just detailed would seem to prove tliat section of the cord is 

 always followed by a decided increase in the giving otf of animal heat, and that 

 the amount of the increase is in direct proportion to the nearness of the section to 

 the brain, provided respiration be not seriously interfered with. 



The following series of experiments shows, however, that this generalization is 

 at least too sweeping. 



E.XI'EHIME.VT 32. 

 A small Spit! dog; wciplit IS llis. 



