THE EVOLUTION OF THE FLOWERS 79 



and it would be very unscientific to imagine first 

 the flower world slowly evolving its attractions, 

 and then imagine the insects discovering the 

 secret in some wonderful way. All through the 

 period of the great reptiles, flowers and insects 

 and their mutual service must have been developing 

 simultaneously. 



But the mighty expansion of the flowers after the 

 severe chill of the Chalk Period would in turn lead to 

 a tremendous growth and rapid development of the 

 insects. We have so often seen the principle on 

 which the machinery of evolution works that it is 

 hardly necessary to repeat it here. It is absurd to 

 imagine a "vital force" pushing evolution in this or 

 that direction. That is merely playing with words. 

 It is equal to saying that "something or other did 

 it," and then imagining that you have explained the 

 matter. 



You understand it much better when you remember 

 that the flowers which were cross-fertilized had the 

 best chance of growing the next generation, and that 

 those flowers had the best chance of cross-fertilization 

 which provided sweet food for insects and some 

 means of letting the insect know that the food was 

 there. Then imagine the broad sunny continents of 

 the Tertiary Era, which we have reached, teeming 

 with flowers. It was still so warm, remember, that 

 figs and bamboos grew in Greenland. There would 

 be an intense struggle among the seed, and the 



