THE CENTRAL SENSORIUM. 603 



developed than the latter, and, like them, transmit impulses of 

 which the primary functional source is the posterior pituitary 

 lody. 



As Regards Afferent (Sensory) Impulses. It has likewise 

 been experimentally ascertained that all fibers that originate 

 from roots in the posterior portion of the cord are afferent: i.e., 

 transmit sensory impulses from the periphery toward the cord. 

 Section of these roots is followed by loss of sensation. 



Interpreted from our standpoint, sensory impressions are 

 similarly transmitted from all parts of the organism, and the 

 one general sensory system supplies the needs of all. The 

 nature of the impulse being governed by the specific cellular 

 characteristics of the peripheral structures which receives the 

 impressions, whether related to a special sense, general sensi- 

 bility, variations of functional activity, etc., they all reach 

 the posterior pituitary. That such is the case is demonstrated 

 by the fact that, while frogs deprived of the hemispheres ex- 

 hibit typical signs of continued co-ordination and sensation, 

 removal of the bulb then causes them to no longer show these 

 signs. This does not exclude the functions of subsidiary cen- 

 ters, i.e., reflex centers, ganglia, etc., which probably serve 

 as accumulators of energy, and act in lieu of the posterior 

 pituitary body unless the peripheral stimulation exceed their 

 potential as to the efferent energy actively used. The law of 

 generalization of Pfliiger, i.e., propagation of (reflex) impulses 

 to the medulla under excessive excitation, which, according 

 to our view, applies to the posterior pituitary, typifies the 

 maximum effect produced under such conditions, and further 

 demonstrates the connection between the periphery and the 

 latter organ. 



Control experiments are represented by the familiar re- 

 sults of stimulation of the dorsal roots, which causes augmenta- 

 tion of reflex activities and of conscious sensations. The reflex 

 inhibition of functional activity of certain organs we have 

 ascribed to excessive stimulation: in accord, therefore, with 

 foregoing facts. This affords the complementary concordance 

 required to place our conception of the functions involved on 

 a solid foundation. 



There is a feature of practical value in this connection 



