230 NEUROLOGY 



readjustment, I will mention three instances of widely different 

 sorts, yet similar, as I think, in principle. These are: First, myxe- 

 dema; next, the vast changes that sweep through the organism at 

 the great climacteric epochs of adolescence and the menopause; and 

 finally, those kindred processes of metamorphosis by which through 

 castration the bull is converted into the ox. 



In all these cases we see two tendencies at work, the one suggest- 

 ing disease, or failure, the other pointing toward the establish- 

 ment of a new sort of equilibrium, containing well-marked elements 

 of stability and health. Is not the controlling principle in these 

 instances analogous to that under which the neuter bee is con- 

 verted into the queen bee through a change in nourishment, or that 

 through which some of the lower forms of marine animals are 

 altered in type by gradual removal from salt into fresh water, or 

 by some kindred modification of the chemical constituents of the 

 fluids by which they are surrounded? 



The conservative physician is usually disinclined to admit bio- 

 logical principles as applicable to the problem of disease. Yet, in 

 fact, it is just in this direction that our search should tend, and 

 when we see complex disorders, such as Graves's disease, or even 

 certain types of neurasthenia, of unknown primary lesion but with 

 hosts of secondary physical and neural signs, we should remember 

 the processes I have cited, and should hesitate before stamping 

 summarily as "disease" modifications of structure and function 

 which doubtless represent, in part, movements toward a new and 

 relatively stable existence. Who can doubt that we ourselves, 

 regarded from another point of view than our own, are defective 

 and mutilated beings, who have sacrificed much to gain the faculties 

 which we justly regard as so important? 



This would be a proper place to mention in detail, at least by 

 way of illustration, some of the more important contributions made 

 by physiologists, psychologists, and biologists, which have thrown 

 light upon the clinical problems of compensation and adaptation. 



I have already referred to the principle of "physiological reserve" 

 force, as utilized by Welch in his important address, and speak 

 of it here again only as possibly helping to explain the numerous 

 instances where the organism shows the power of fostering certain 

 of the functions of the nervous system at the expense of other 

 manifestations of its life. The case of the runner from the field of 

 Marathon, who brought his message to Athens in spite of the gath- 

 ering dissolution which laid him dead in the market-place at the 

 moment of his arrival, is a striking illustration of a principle which 

 is of frequent application. 



Thus, the disarrangements of the nervous system that are liable 

 to follow nervous shocks of some severity are sometimes very late 



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