3i6 THE LIFE OF THE PLANT 



seldom when it is fully developed), that there exists a 

 series of transitional forms, and the most important 

 of the three that this transformation is useful to the 

 organism itself. Then it becomes obvious that under 

 the influence of natural selection such a form not only 

 might, but necessarily must, have arisen. 



Hence the explanation of the harmony, of the per- 

 fection of the organic world, suggested by Darwin 

 does not turn out to involve any a priori endow- 

 ment of the plant with a tendency towards perfec- 

 tion, with any inborn progressive activity. On the 

 contrary, according to that theory, variations as 

 such may equally well be useful or harmful. But 

 owing to selection every harmful variation, precisely 

 because of its harmfulness, is doomed to extermination 

 sooner or later, whereas every useful adaptation is 

 transmitted to future generations. The general pro- 

 gression, the drift towards perfection, is effected by 

 exterminating everything that is harmful, and by 

 accumulating slowly and gradually useful properties. 

 Thus the perfection of the organic world no longer 

 appears in itself as an incomprehensible end, but as an 

 eminently conceivable result of authentic natural causes 

 well known to everybody. 



Curiously enough another great thinker came to a 

 similar conclusion before Darwin ; with the difference, 

 however, that according to the current ideas of his time he 

 could not admit the theory of the mutability of species. 

 Auguste Comte writes as follows in the third volume of 

 his Positive Philosophy : ' Without doubt every organ- 

 ism finds itself necessarily related to a certain combina- 

 tion of external conditions. It does not at all follow, 

 however, that the former of these two correlated forces 

 has been produced by, any more than it could have 

 itself produced, the other. We have simply to deal with 

 two forces in a state of equilibrium, totally independent 

 of each other as also essentially different. If we imagine 



