PLANTING AND MAINTENANCE 119 



portance. Take care of these and the roots will 

 take care of themselves — almost. For every 

 tiny, hair-like root filament is a hungry little 

 mouth, and the greatest tree is as dependent 

 upon these as the humblest little annual, its 

 massive woody roots being actually no more 

 than anchors. 



Contact with the food is the first mechanical 

 essential to feeding, in either the vegetable or 

 animal kingdom. The food of plants is taken 

 in solution from the earth; in other words it is 

 a liquid diet strictly, and it is absorbed through 

 the delicate walls of these tiny, soft, tender 

 little feeding rootlets, then passes up along the 

 canal (which runs through even the tiniest) 

 into the larger rootlets whence these spring, 

 and so on, up and up until the main "trunk 

 line" is reached; and then still up into branch 

 and twig and leaf, every part receiving due pro- 

 portion of its particular requirement as the 

 transit is made. Finally, through the leaves, 

 the water, strained of its organic and mineral 

 content, is transpired and returns to the at- 

 mosphere. In the course of a single summer 

 day an ordinary tree will yield fifty gallons of 

 water — perhaps much more — under the insis- 

 tent heat of the sun. And vegetation generally 

 is calculated as transpiring horn, forty to one hun- 



