24 THE SURVIVAL OF THE UNLIKE. [l. 



this does not prove that those which are lost are any the 

 less dne to the impinging stimuli. Those who write of 

 definite variation nsually constnie the result or outcome 

 of some particular evolution into a measure of the vari- 

 ation which is conceived to have taken place in the 

 group. Most or all of the present characters of any 

 group are definite because they are the survivals in a 

 process of elimination; but there may have been, at va- 

 rious times, the most diverse and diffuse variations in 

 the very gi'oup which is now marked by definite attri- 

 butes. As the lines of ascent developed, and generation 

 followed generation in countless number, the organiza- 

 tion was more and more impressed with the features of 

 ancestral characters, and these ancestral charactei-s are 

 the more persistent as they have been more constant in 

 the past. But these characters, which appear as hered- 

 itary or atavistic variations in succeeding generations, 

 were no doubt first, at least in the plant creation, the 

 offspring, for the most part, of the environment react- 

 ing upon the organism. As life has ascended in the 

 time -scale and has become increasingly complex, so the 

 operation of any incident force must ever produce more 

 diverse and unpredictable results. What I mean to say 

 is that, in plants, some of the variations seem to me to 

 be the resultants of a long line of previous incident im- 

 pressions, or to have no immediate inciting cause. Such 

 variation is to all appearances fortuitous. It is, there- 

 fore, evident that the study of the effects of impinging 

 environments at the present daj' may not directly eluci- 

 date the changes which similar conditions may have pro- 

 duced in the beginning. 



Whilst the steadily ascending line of the plant crea- 

 tion was fitting itself into the changing moods of the 



