CONCLUSION 181 



long outgrown their use), and the morphology of the 

 flower will be greatly simplified. 



Thus we can foresee on both sides much simplified 

 individual flowers- in the one group the reduced indi- 

 viduals associating together in communities the members 

 of which are highly specialized, and in the other the 

 solitary flowers becoming less elaborate and conspicuous, 

 as they no longer need the assistance of insects (the 

 cleistogamic flowers of the Violet, for example, even in 

 the present day bend toward the earth, and lack all 

 the bright attractiveness of ordinary flowers), and per- 

 haps finally developing underground, where the seeds 

 could directly germinate. 



In the vegetative organs less change is to be ex- 

 pected, the examples from the past lead us to foresee 

 no great difference in size or general organization of 

 the essential parts, though the internal anatomy has 

 varied, and probably will vary, greatly with the whole 

 evolution of the plant. 



But one more point and we must have done. Why 

 do plants evolve at all? Why did they do so through 

 the geological ages of the past, and why should we 

 expect them to do so in the future? The answer to 

 this question must be less assured than it might have 

 been even twenty years ago, when the magnetism of 

 Darwin's discoveries and elucidations seemed to obsessj 

 his disciples. " Response to environment " is un- 

 doubtedly a potent factor in the course of evolution, 

 but it is not the cause of it. There seems to be some- 

 thing inherent in life, something apparently (though 

 that may be due to our incomplete powers of observa- 

 tion) apart from observable factors of environment 

 which causes slight spontaneous changes, mutations, and 

 some individuals of a species will suddenly develop in 

 a new direction in one or other of their parts. If, then, 

 this places them in a superior position as regards their 

 environment or neighbours, it persists, but if not, those 

 individuals die out. The work of a special branch of 



