580 THE POSTERIOR PITUITARY AND THE NERVOUS SYSTEM. 



The bearing of this arrangement, as an element of func- 

 tion, asserts itself when the stress we have laid upon the vibra- 

 tory character of a nervous impulse is recalled. When study- 

 ing the nature of the functional activity of muscles, we had 

 occasion to say, referring to the governing action of motor 

 nerves: "As the vibratory rhythm of the impulse and that of 

 the muscle always correspond, any variation of rhythm by the 

 brain-center correspondingly modifies the muscular contrac- 

 tion." If we now analyze what this vibratory rhythm means 

 when the dendritic end-bulb and the axonal end-bulb are sepa- 

 rated by an infinitesimal distance, but one answer appears to 

 suggest itself: i.e., that there can be no flow of impulses from 

 one to the other. But we must not lose sight of the fact that 

 the contradictory histological pictures described by Cajal and 

 Berkley are those of non-living cellular elements, and that 

 death may leave the two end-bulbs juxtaposed, as seen by Cajal, 

 or separated by an "infinitesimal distance," as seen by Berkley. 

 Thus, each histologist is right in his way as regards dead tissue. 

 But what of living structures? Cajal and Berkley will again 

 assist us in reaching a deduction in this connection, for each 

 investigator furnishes one-half of the main physical function 

 involved: i.e., vibration, which, means rapidly alternating jux- 

 taposition and separation of the 'bulbous end-organs. 



The rapidity with which the gap between the two terminals 

 is opened and closed i.e., the rhythm regulates, we have seen, 

 functional activity. But can we conclude from this that non- 

 activity of an organ means cessation of vibration of the bulbous 

 end-organs involved in the function? We have seen that the 

 nutritional processes of all tissues are continuous, nervous 

 energy being supplied to the cellular elements as long as life 

 lasts. Forel, as stated, was led by his admirable investigations 

 to the conclusion that "living muscle appears to be so organized 

 that without nervous stimulation it can live as little as the 

 tropical animal can without warmth or the rose without water." 

 This applies to all living tissues: a feature of the problem 

 which necessarily implicates the continuous development of 

 nervous energy and, as a consequence, an unceasing vibration 

 of the end-organs. It seems to us, therefore, that, inasmuch 

 as the nutritional processes of the organism require a continuous 



