110 SYMBIOGENESIS 



its origin and efficiency are due to appropriate symbiotic 

 activities. 



On Mr. Pickering's showing, the welfare of a tree in 

 general depends on its ability to send out new roots from the 

 stem, in order that these roots may come into as close as 

 possible contact with the soil. It is significant in this connec- 

 tion that as a result of protracted experiments Mr. Pickering 

 and others, in considering the best treatment of trees, came to 

 conclusions which are calculated to confirm, also in other 

 particulars, the view here taken of the building up of capital 

 and of Bio-Dynamics in general. 



Secondly, we may turn to the effects of pruning. It has 

 been recently established as a fundamental principle, that 

 " the less pruning there is, the more will a tree grow, and the 

 more fruit will it bear." 



It is true that this does not altogether remove the necessity 

 of pruning for purposes of shape, but the discovery that con- 

 tinued annual pruning is harmful to the welfare of the tree, 

 runs counter to many of the identical prejudices with which I 

 have throughout to contend in promulgating my bio-economic 

 theory. 



While pruning is justified and, indeed, necessary on horti- 

 cultural grounds, men are apt to go on to infer that mutilation 

 itself is advantageous on the same line of thought which 

 advocates hunger and hardships as spurs of industry. Used 

 to thoughtless abuse of bountiful nature, man has too long 

 been satisfied to rely immoderately on the rough principle that 

 the more you stimulate an organism by pain and mutilation, 

 the more you call forth efforts on its part to make up in other 

 directions. But although endowments are vast and ancient, 

 there is a limit to which they can be drawn upon. Regenera- 

 tion and reaction to destructive action have their limits, and 

 stimulation and mutilation largely fail of their usual effect 

 where a due compromise between racial expenditure and bio- 

 economic contribution has already been established by a 

 species. 



