339 
On Reciprocal Innervation in Vaso-motor Reflexes and the 
Action of Strychnine and of Chloroform thereon. 
By W. M. Baytuiss, D.Sc., F.R.S. 
(Received January 20,—Read March 12, 1908.) 
(From the Physiological Laboratory of University College, London.) 
CONTENTS. 
PAGE 
MPMUHIETOCUCCOLY: isons ccmavcks << soled td neem dee «tarsn vharsée’ 339 
II. Reciprocal Innervation in the Normal Animal............ 341 
it. Depressor Retlexesrstsse.cs<- 2. tae etic. ces se cancoe seas. 341 
(i) Excitation’ of Wilators: Joi.) 0 icc. ccblcavedincs oven 342 
(ii) Inhibition of Constrictors ...............sc0seee8s 347 
Zoe TessOr, ReNOKECS. cn nt. deans stagscse Jags dietrsepsoacyarduccnes 349 
(1) Hixeitatiom-of CoOnstrictGEs 4...-2.<..<.ss-0c0rd<es 349 
Gi)" Tivhibrtion, Gf Wilators 2.5.0... cc.cceseceecesoceses 349 
epi OMG UECHOMEAG Cue ycrs 4) cdncl cu sb esd vawalsthhoscea chews 351 
EE The, Action) Of  Stey CHM «4.50000 cuenesineensacin-vaersecesdes 353 
IWes Dhe Atctiom Of CMlOrgtOri,....ss<00ca+edosneoedendeenaseaeveces 365 
Wes Clemens leEvomat ks 57.55 eatcasnseacasdh sau seee ovevaeieednsadeedesis 370 
Wy Summary of Conclusions ........).iecccilesoncceecdssowensesese 374 
I. INTRODUCTORY. 
In a paper published in the year 1893, after describing various experimental 
results on vascular reflexes, I made use of the following words: “the simplest 
explanation of the above results is the hypothesis that the vaso-motor centre 
consists of a constrictor and a dilator part, the depressor nerve acting in an 
inhibitory manner on the former, and in an exciting manner on the latter, 
while pressor nerves act in an opposite way on both.”* 
The evidence brought forward at that time in support of this view was 
mainly indirect, and in no way comparable with the brilliant experimental 
proofs afforded by Sherrington’s masterly researches on the similar phenomena 
in the case of the reflexes to voluntary muscles. These latter results have, 
however, given renewed interest to the question, and the following pages 
contain an investigation whose object was to obtain direct experimental 
evidence whether or not the phenomena of vascular reflexes can be brought 
into line with those affecting skeletal muscle. 
Since the publication of my paper referred to, certain incidental observa- 
* “On the Physiology of the Depressor Nerve,” ‘Journ. of Physiology,’ vol. 14, p. 317, 
1893. 
VOL. LXXX.—B. 2% 
