THE CIRCULATION OF CBREBRO-SPINAL SUBSTANCE. 573 



are not supplied with vasomotor nerves. "Vascular nerves may 

 be found without trouble or difficulty in muscles, glands, etc., 

 by the silver and other stains/ 7 writes Berkley, "but in the sub- 

 stance of the encephalon they are never to be seen with similar 

 staining methods; hence it is fairly reasonable to suppose that 

 they are not present in this location and that some other con- 

 trolling mechanism takes their place. I have most carefully 

 looked for them in many brains, both human and of the lower 

 animals, but have never seen the slightest trace of their pres- 

 ence within the nervous structures. . . . Tuke and An- 

 driezen, who made researches in the same field, have also failed 

 to find them." As we will have occasion to show, this is an 

 extremely important factor in the pathology of all toxemias, 

 mental and nervous diseases, for it indicates that stimulation 

 of the adrenal system by toxics of any kind causes vascular en- 

 gorgement of the vascular channels of the brain-substance simul- 

 taneously with the engorgement of the peripheral capillaries of the 

 other parts of the organism. 



Under these conditions contraction of the central vascular 

 trunks through excessive adrenal activity causes not only con- 

 gestion of the surface, but also of the brain. Strikingly con- 

 firmatory of this fact are the following statements of Professor 

 Foster's: "It is argued that, in the absence of vasomotor nerves 

 of their own, the cerebral vessels are wholly, so to speak, in 

 the hands of the general motor system; so that when the blood- 

 pressure is high, owing to a large vasoconstriction in the ab- 

 dominal viscera, more blood must necessarily pass to the brain, 

 and when, again, the pressure falls, through the opening of the 

 splanchnic flood-gates, less blood necessarily flows along the 

 cerebral vessels." . . . "Again it has been observed that 

 certain drugs have an effect on the volume of the brain quite 

 incommensurate with their effect on the vasomotor system." 



If our views are sound, i.e., if our interpretation of the 

 data available is exact, our conception of the neuron's inherent 

 functions coincides with some of the main conclusions reached 

 by Deiters, Gerlach, Golgi, Forel, and Cajal. In outlining the 

 conclusions to which these investigators were led, however, we 

 will only refer to those which are directly connected with our 

 own inquiry. 



