Xo. 49S] 



PHYSIOLOGY 



medical schools and its continued close association with 

 them, as a result of which the attention of investigators 

 and teachers has been necessarily focused largely upon 

 internal problems. This aspect of the science is mir- 

 rored in the text books, and is the chief aspect that is 

 presented to the youth in his early studies. Unfortu- 

 nately the university student has only a limited oppor- 

 tunity to correct his early false impressions, for the 

 university has not yet accorded to physiology its rightful 

 heritage as a pure science. Its freedom in research 

 can not be denied it, however, and popular misconceptions 

 regarding its scope will disappear with its advance. The 

 living of the living thing is the criterion by which the 

 physiological phenomenon may be recognized. 



The ways in which the vital process manifests itself 

 seem at first sight numberless and incapable of mutual 

 comparison. The contraction of a muscle, the secretion 

 of a glandular product, the production of a sensation, the 

 growth of an organism, the orientation of a motile body 

 to rays of light, the passage of a nervous impulse, respira- 

 tion, the circulation of blood, the transmission of a 

 quality from parent to offspring, instinct, fatigue, a voli- 

 tional act, the course of a germ disease, sleep, speech, 

 laughter, thought, the digestion of food, the maintenance 

 of bodily temperature, the hearing of sound siirht the 

 recognition by touch of a familiar object, memory, 'emo- 

 tions, the inhibition of an existing action, hypnosis— at 

 first thought these phenomena appear to be of quite dif- 

 ferent kinds, each sui generis and incapable of com- 

 parison with the others. Have they common factors? 

 Is it possible to unify them? 



Through the ages various attempts have been made to 

 do this. The appearance of the first of these attempts 

 was nearly coincident with the culmination of Grecian 

 culture. From that auspicious time down to the great 

 Roman physician Galen, then across the long stretch of 

 thirteen centuries, bridged by Galenic tradition, but 

 barren of physiological discovery, to the rebirth of scien- 



