Conifers 



squirrel; then the next side shoot grows upwards and 

 becomes a leader. Yet in a general way there are 

 distinct differences both in growth and in behaviour to 

 light of the main horizontal branches, and of those of 

 the third and fourth order which spring from them. 



In some conifers (Cupressineae), if one makes a 

 cutting from one of these side-shoots, it may grow into 

 a tree, but always preserves its side-shoot character, 

 never growing properly like cuttings from a leading 

 shootJ The amount of light required by the different 

 trees, shrubs, and herbs differs enormously. 



Box can grow even in shade so deep that only 

 one-hundredth part of the daylight reaches it. Young 

 beech trees wdll form abundant leaves even in only one- 

 fourth of the natural daylight.^ 



Similar differences are found in the behaviour of the 

 herbs and other ground vegetation. When, e.g.y a great 

 tree falls and light reaches the wood-floor, numbers of 

 seeds, which had lain for years in the leaf mould, 

 suddenly germinate. Other roots and rhizomes which 

 had gone on stolidly living and forming perhaps a very 

 few leaves every year, or tying up the ground by long 

 branching runners without ever flowering at all, these, 

 as soon as the genial sunshine touches them, awake to 

 full activity and grow and flower luxuriantly. 



A very few, such as Dentaria bulbifera, prefer the dark 

 shade and moist humus of the closer parts of the forest. 



Supposing, however, that such a clearing is planted 

 with young conifers, they have at first a struggle against 

 the nettles 5 or 6 feet high, perhaps 6 feet of bracken or 

 quick springing brooms, birches, and whins ; but so soon 

 as their branches begin to touch one another, the under- 

 growth begins to vanish away. No seeds germinate, and 

 the perennials return to subterranean runners and roots. 



The branches of the treesthen begin to compete among 



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