346 Problems of Organic Adaptation 



but in 1909 I suggested that it might be applicable to many 

 other organic reactions. ZurStrassen has generalized this 

 principle under the title "overproduction of opportunities 

 (Gelegenheiten)." If this principle should be found appli- 

 cable to physiological responses in general it would explain 

 in equally simple manner many apparently purposive re- 

 sponses which are at present inexplicable. It is known, for 

 example, that immunity to bacterial or other toxins is not 

 acquired immediately but only after a certain lapse of time 

 during which physiological processes are more or less dis- 

 turbed; there is frequently an increase of destructive me- 

 tabolism, the body temperature rises, and there are other 

 abnormal conditions. "Fever is the process of adaptation 

 to such toxic agencies as can be neutralized by the develop- 

 ment of anti-bodies" (Adami and McCrea, p. 149). It is 

 at least possible that during this period the responses to the 

 toxin are in the nature of trial and error, that many kinds 

 of anti-bodies are formed, and that the production of useless 

 kinds gradually ceases while beneficial ones continue to be 

 formed. This last might be explained as a result of the 

 establishment of chemical equilibrium, for if many kinds of 

 anti-bodies are formed and only one is used up in the "fixa- 

 tion" of a toxin, this one would continue to be formed while 

 the other kinds would not. 



If this suggested explanation of individual adaptations 

 should prove to be true, it would mean that the living, de- 

 veloping, reacting organism is like a swimming Paramecium ; 

 it tries many paths, eliminating or ceasing to follow useless 

 or injurious ones and persisting in the beneficial ones. Such 

 an hypothesis implies in many cases the capacity on the part 

 of organisms to distinguish between harmful and beneficial 

 conditions, and this capacity is left unexplained. Since it 

 is present, however, in living things generally, it may be 



