1908. | Innervation in Vaso-motor Reflexes, etc. 373 
posture of the body were those in the main affected. Now there is an 
obvious point of similarity between these muscles and the arterial wall, 
which consists in the circumstance that both are normally in a condition of 
tone. It is, as Professor Sherrington has suggested to me, a question worth 
C.C. 
Fig. 28.—C and D. Constrictor and dilator efferent neurones. A. Arterial muscle-cell of 
body generally. K. Ditto of organ (e.g., kidney) from which the afferent fibre 
R passes to the bulbar centres, giving off collaterals to the spinal centres. 
The connections of this fibre are such that it excites constrictor centres:in the 
bulb and dilator centres in the cord, while its relations to the dilator centres 
in the bulb and the constrictor centres in the cord are inhibitory. 
investigation whether there is any special connection between the vaso- 
motor centres and the labyrinth. 
The statement is sometimes made that strychnine causes excitation 
of constrictors to the viscera and of dilators to the skin. This is not quite 
the correct way of expressing what happens on injection of the drug. 
: | 2a 2 
