THE ERA OF HELPLESSNESS 39 



been found in which such a thing has occurred in 

 the natural course of events. This one having been 

 overlooked in the past, the rule that "no traits 

 can be preserved or enhanced unless they are of 

 advantage in adaptation at every step in the pro- 

 cess," * that is to say, in every generation, has here- 

 tofore been regarded as holding without exception. 

 The question then arises, under what kind of con- 

 tingencies, if any, in the natural course of events 

 could the last few of an unadapted form of life 

 be prevented from interbreeding with the variety 

 from which they are only distinguished by slight 



1 The validity of this rule, which has been maintained by 

 scientists since more than a century, rests, firstly, on an enor- 

 mous array of observations which establish these two points, 

 viz., that the normal average types of the organisms of highly 

 specialized species and races, since time immemorial, have tended 

 to persist and prevail most tenaciously throughout changes in 

 outward conditions; that new traits, on the contrary, are fre- 

 quently found to be modified by such changes ; secondly, the rule 

 follows, also, as an inference from the inherent results of time 

 and the general commotion of all things in the universe. These 

 two, reacting on the intricately commingled forces and materials 

 of organic individuals, must inexorably tend to a concentration 

 within them of like with like and dissociation from unlike. 

 From this dissociation or expulsion of the foreign results a puri- 

 fication of the constituent materials and forces. The longer the 

 time during which a type has existed, the longer this process 

 has continued, therefore the greater this purification. The 

 greater their purification, the more confirmed and established 

 the inherent tendencies of the original constituents of an organ- 

 ism must become, and the less liable they must be to disturb- 

 ance. 



Since new traits must be the result, of either new materials 

 or new molecular or structural arrangements which have not 

 had time to become confirmed or established, therefore must 

 they be exceedingly liable to modifications and unable to resist 

 modifying influences. They therefore can only continue if they 

 are favorable to adaptation and therefore naturally selected. 

 For better comprehension, see Appendix, Note IV. 



