The Internal Secretory Organs 

 their Physiology and Pathology. 



PART I, -GENERAL 



HISTORICAL AND INTRODUCTORY. 



WE have long been aware of a reciprocity of activity between 

 different parts of the body, and this inter-relation of function is 

 called the consensus partium. But, until very recently, the 

 haziest ideas prevailed as to the manner in which the individual 

 organs react upon one another and the mechanism by which their 

 interbalance is maintained. 



We are now, however, in a position to advance the logical 

 postulate, that the mediating agents can be those only which, while 

 having access to each organ, yet come together at a common 

 centre. The central nervous system supplies an excellent example 

 of such a mechanism, affecting and controlling as it does the 

 correlation of the various physiological activities. Messages are 

 carried by the centripetal nerves from the extreme periphery to 

 the centre, and this centre is enabled, by means of the centrifugal 

 nerves, to convey ever-changing impressions to different parts of 

 the body. When the so-called " reflexes " were discovered, partly 

 by Descartes in the lyth, and finally by Prochaska in the iQth 

 century, the prompt and purposeful intervention of the central 

 nervous system in the regulation of organic function became 

 firmly established. 



An impression conveyed from the periphery to the nervous 

 centre will excite activity in an entirely different part of the body. 

 Though this is accomplished without the assistance either of the 

 consciousness or of the will, it is neither casual nor purposeless 

 in its happening. On the contrary, the degree of activity is 

 calculated to the needs of the organism and is in accordance with 

 changes in the conditions surrounding it. This reflex character 

 is in part congenital and is an integral factor in the organization 

 of the nervous system ; in part it is acquired, and is the result 

 of habits formed during life. By its means the co-ordinated 

 activities of the different parts of the body are regulated and 

 controlled and it was for this reason that scientists until recently 



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