THE ARCHITECTURE OF TREES 157 



for all emergencies, it is true ; but no more than 

 this can be said of buildings. They have also 

 beauty ; which is a constant source of delight 

 to us. What about utility ? 



Here we must walk warily. It can be said 

 at once, of course, and will immediately have 

 come to the reader's mind, that trees are useful 

 for their timber. But in this sense they are 

 only useful when they have ceased to be trees. 

 They are useful for shade ; to this limited 

 extent they serve the purpose of buildings ; and 

 how much this service they render us counts 

 for in the pleasure with which we look at them 

 or at any pictorial representation of them we 

 have already seen. Their fruits and other 

 parts of them are variously useful to us ; and it 

 is mainly or even wholly for this reason that 

 many trees are grown. We train them, and 

 even partly change their nature, grafting one 

 tree on another, in order to increase their use- 

 fulness. And if it will serve our purpose to do 

 so, we even cut short their life. Ah! Here 

 is another quality ; one that Vitruvius does not 

 mention with regard to buildings — Life. We 

 have already spoken about it ; but we must not 

 forget it in relation to tree-architecture. In 



