Trees. 317 



Again the wind adaptations. Think of the stresses and 

 strains in a forest tree in a gale of wind. Look at the heights 

 of an Eucalyptus amygdalus, 456 feet, 120 feet above St. 

 Paul's; mammoth tree, 426 feet; silver fir, 225; spruce, 180; 

 Scotch fir, larch, and cypress, 159; yew, 45 feet. Even sun- 

 flowers may be 17 feet high in America. All this is arranged by 

 the specialisation of the myriads of living and dead organisms 

 which go to make up the tree. 



Generally, it seems as if any one of these organisms had to 

 do exactly what was best for the good of the w^hole tree, accord- 

 ing to the position in which it has been placed. In which case 

 our own societies and civilisations appear to be distinctly on an 

 inferior level. Yet these little living units are often called 

 upon to become something quite different. Supposing you cut 

 into the tree. Those cells that are wounded are at once cut 

 off from the rest. The nearest living cells are sacrificed; they 

 are changed into cork, stoppered with gum, or sometimes with 

 indiarubber, and the wound is promptly healed. A rampart 

 of dead bodies is built up over the spot. But it is not only in 

 themselves, but also as sheltering organisms that trees are im- 

 portant. On the bark of a tree we find seaweeds — pleurococcus. 

 On the branches lichens and mosses. Most people consider 

 these to be useless except to themselves. That is not so. 

 Those low forms of life occupy spaces where light would be 

 wasted, and their dead material falls eventually to the ground 

 and manures it. They add to the valuable leaf mould regularly 

 formed. The fungi on the ground are even more important, 

 for it is by their fine insinuating and dissolving threads that all 

 this dead material is broken up, modified and prepared for 

 absorption by the trees again. The ferns, hyacinths, anemonies, 

 the brambles, and rasps in the wood, all add to the efficiency of 

 the wood which shelters them. The leaves are gradually broken 

 up, and practically nothing once formed is ever lost. 



Finally such woods usually fall under the axe of the 

 lumberer. The wood itself is an essential ; it is necessary for 

 human civilisation. Seven acres of forest are required for a 

 day's issue of one New York paper. The end may, we hope, 

 justify the destruction. Then upon the site of this w'ood home- 

 steads and fields of wheat, and oats, and barley are farmed. 



