-4 FKVKR. 



The rt'sults of our whole- study as to the efticts of separation of the nicdulhi from 

 the pons upon tlieruiogenesis niav be forujulateil as follows : Section uf thv vmlulla 

 at il« junrlinn trith the jions w j'olhncttl lnj iiu-rcuficil heat difti:ij>iUion ami iiicittuetl 

 J, htrlion, tin- inrrniHril i/isnijHitUiu nxitaUij nut kiijiiinj piue trilfi tfu iucreuaal 



J,,,.,..- ..-Ill, HO that tlif fHMflli/ ttiiijurutuiv riitn. 



The question which naturally arises at this stage of our investigation is as to 

 the cause of the phenomena which follow superior medullary section. In v(i,Mrd 

 to the heat dissipation, it is apparently simidy the result ot the increased heut pro- 

 duction, a warmer body naturally giving off niore heat than a cooler one. "Slnic. 

 than this, the vaso-motor s) stem being intact, /. »., the normal nu-chanism for cooling 

 the body being jm-served, it is inevitable that tlic living animal organism, which 

 is prodm-ing heat more rapidly than normal, should endeavor to cool its body us 

 rai)idly as possildc so as to get rid of the excess of heat. 



Increased heat ])roduclion being then the cause of the increased heat dissipation, 

 the probU-m i)resents itself — what is the cause of the increased heat production I 



Various explanations have been offered to accoiuit for the rise of bodily tem- 

 perature which follows the separation of the medulla from the pons. One set of 

 investigators believe that it is due to irritation of the vaso-motor centres. It is, 

 however, a geiu'ral guiding principle in making deductions that section of a nerve 

 induces abolition of funclion aiul that the symptoms which follow such section are 

 paralytic unless clearly proved to be of other nature. Ili'idenhain, who has esjxj- 

 cially iulvocated the irritation theory, states that he was led to his conclusion by 

 noting that the rabbits, upon which Bruck ;ind Ciiinter experimented, bhowcd 

 svniptoms of irritation of the medulla in that their breathing was exceedingly rapid. 

 .\(ling upon this, he suggested that the effect of puncture shoidd be tried, and 

 accordingly liruck and Giiuter instituted such experiments. {Pjliijirs Aniiir, Ud. 

 iii. p. o7i).) Tlir temperature rose more xuiiformly than in the previous experi- 

 ments in which section was practised. It was fonnd that two or more pmictures 

 were more eft'ectual than a single one, and that the effect was still more pro- 

 noiniced, if two of the lancoshapid needles were plunged in at once, and allowed 

 to remain. (Am siciiersten darf man auf die Temperatur-Sleigerung reclinen, 

 wcnn man zwei Nadeln in eincr Ebene, die ungefiihr 1 mm. vor dem tuberctdum 

 interparietule liegt, jederseits 2 nnn. von der Mcdian-Klx lie in das (jiehirn scukt 

 und diesellnu liegeii liisst.) 



It is evident that in the experiment of Bruck and Ciiinter, the nerve centres 

 were actually wounded, and I sec no reason for disbelieving the possibility of this 

 wound affecting the conducting power of the nerve fibres, especially as it is plain 

 that the deeper and l.-frger tin- wound, i. c, the more numerous the needles, the 

 greater was the rise in tenii»erature. The paralytic effect of plunging a lance- 

 sliaiMHl needle into a nerve centre certainly reaches, at least for a time, beyond tJic 

 obvious wound, and the effect of leaving a needle in must be to increase this pani- 

 lysis by pressure. The reason the rise was obtained more freqmntly after the 

 puncture than after the .section of the medulla, se(>ms to me to depend upon the 

 circumstance that in the former case the vaso-motor ceutiis were not so apt to be 

 involved as in the latter. (See page fil.) 



