GENERAL PRINCIPLES OF MORPHOGENESIS 121 



plain. Conventional methods of anatomical research have laid a se- 

 cure factual foundation, but the superstructure must be designed on 

 radically different lines. Several centuries of diligent inquiry by 

 numerous competent workers have produced a vast amount of pub- 

 lished research on the anatomy and physiology of the nervous sys- 

 tems of lower vertebrates; but most of this literature is meaningless 

 to the student of the human nervous system, and, as mentioned at 

 the beginning of this book, its significance for human neurology has 

 until recently seemed hardly commensurate with the great labor 

 expended upon it. The last two decades have inaugurated a radical 

 change, in which we recognize two factors. 



In the first place, technical improvements in the instrumentation 

 and methods of attack have opened new fields of inquiry hitherto 

 inaccessible. To cite only a few illustrations, new methods for the 

 study of microchemistry and the physical chemistry of living sub- 

 stance, radical improvement in the optical efficiency of the com- 

 pound microscope, the invention of the electron microscope, and the 

 application of the oscillograph to the study of the electrophysiology 

 of nervous tissue are opening new vistas in neurology, which involve 

 quite as radical a revolution as that experienced a few centuries 

 earlier when microscopy was first employed in biological research. 



A second and even more significant revolution is in process in the 

 mental attitudes of the workers themselves toward their problems 

 and toward one another. A healthy skepticism regarding all tradi- 

 tional dogmas is liberating our minds and encouraging radical inno- 

 vations in both methodology and interpretation. And, perhaps as a 

 result of this, the traditional isolationism and compartition of the 

 several academic disciplines is breaking down. The specialists are 

 now converging their efforts upon the same workbench, and co- 

 operative research by anatomists, physiologists, chemists, psycholo- 

 gists, clinical neurologists, psychiatrists, and pathologists yields re- 

 sults hitherto unattainable. What is actually going on in the brain 

 during normal and disordered activity is slowly coming to light. 



Here the comparative method comes to full fruition, and compara- 

 tive morphology acquires meaning, not as an esoteric discipline deal- 

 ing with abstractions but as an integral and indispensable component 

 of the primary task of science — to understand nature and its proc- 

 esses and to learn how to adjust our own lives in harmony with 

 natural things and events, including our own and our neighbors' 

 motivations and satisfactions. 



