218 THE RING OF NATURE 



the soul of man not yet within several million 

 years of his birth. 



The flies seldom finish off a sporangium so 

 cleanly, but there are spores to link arms and fly 

 away about their business. But now arms are 

 apt to be linked by spores of distinct plants mixed 

 in one sporangium by the flies coming dirty-legged 

 from one plant to another. These, in spite of the 

 fact that they are as yet asexual bodies, will 

 produce a stronger progeny, or one better able 

 to exist in some locality mid-way in dryness or 

 other quality between those of the parent plants. 

 For reasons such as this the greater number of 

 successful offspring will result perhaps not from 

 the plant that best succeeds in avoiding the flies, 

 but the one that is most eaten. There is even a 

 premium set on attractiveness, and straightway 

 the vista is opened to all the floral beauties of our 

 own day. 



We know how responsive are our own bodies to 

 stimuli from outside. One look at the horny 

 hand of toil will give us a satisfying example. 

 From everything we see, it appears that the 

 vegetable organism is far more susceptible than 

 the animal in this physical respect. The endless 

 variety of tumid and hairy growths fetched up 

 in the trees and plants by the bites of gall-flies 

 is a striking example, and it will be seen that 

 every tree responds in its own special way to the 

 assault of the pruning knife or the nibbling of 

 rabbits or cattle. 



