PREFACE 



THERE are two groups of functions performed by the nervous 

 system which are of general interest; these are, first, the physio- 

 logical adjustment of the body as a whole to its environment 

 and the correlation of the activities of its organs among them- 

 selves, and, in the second place, the so-called higher functions 

 of the cerebral cortex related to the conscious life. The second 

 of these groups of functions cannot be studied apart from the 

 first, for the entire conscious experience depends for its materials 

 upon the content of sense, that is, upon the sensory data received 

 by the lower brain centers and transmitted through them to the 

 cerebral cortex. Since the organization of these lower centers is 

 extremely complex, and since even the simplest nervous proc- 

 esses involve the interaction and cooperation of several of these 

 mechanisms, it follows that an understanding of the workings 

 of any part of the nervous system requires the mastery of a large 

 amount of rather intricate anatomical detail. 



Fortunately, the knowledge of the precautions which must be 

 observed in order to maintain the nervous system in healthy 

 working order is not difficult of acquisition (though surprisingly 

 few people seem to have gained it), just as any one can learn to 

 operate an automobile, even though quite ignorant of the engi- 

 neering problems involved in its design and construction. In- 

 formation regarding these matters of practical hygiene is readily 

 available, 1 and it is not the primary purpose of this book to sup- 



1 GULICK, LUTHER H. 1907. The Efficient Life, New York. 



GULICK, LUTHER H. 1908. Mind and Work, New York. 

 ^ JEWETT, FRANCIS GULICK, 1898. Control of Body and Mind, New York, 

 Ginn & Co. Adapted for use in the graded schools. 



LUGARO, E. 1909. Modern Problems in Psychiatry, Manchester 

 University Press. A book written especially for physicians, but full of 

 stimulating ideas for every educated reader. 



STILES, P. G. 1914. The Nervous System and Its Conservation, Phila- 

 delphia, W. B. Saunders Company. 



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