CHAPTER I 



THE STRUGGLE FOR EXISTENCE 



When a seedling lias germinated, it proceeds to push 

 the radicle into the ground, and this becomes the taproot 

 of the plant, while the plumule, which lengthens itself 

 above the ground becomes its stem. Both the stem and 

 the root continue to lengthen for some time without 

 branching I am dealing mainly with dicotyledonous 

 plants but ultimately branchlets and rootlets are given 

 forth from the main axis. If the seedling stands in 

 an isolated position its various members will lengthen 

 and give out more branches, and the development of the 

 latter may even be so great as to be equal to or greater 

 than that of the main axis. Isolated trees have com- 

 paratively large crowns and short boles, and it may even 

 happen that side branches persist on the stem at a 

 distance of only a few feet above the ground level. 



When the seedling is only one of many of the same 

 age, the lateral development goes on till the branches 

 and roots meet those of the other seedlings, and from 

 that moment a struggle begins between the various 

 individuals of the seedling crop for mastery of air and 

 light above ground and for the possession of the soil. 



If the seedlings are not only of the same age but also 

 of the same species the struggle is the most even of all ; 

 but ultimately some of the individuals are left behind in 

 the race, their crowns get compressed by those of their 

 stronger neighbours, and only the tips are able to get 

 direct sunlight and to assimilate food, and eventually 



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