TREE-FORM OUT OF ITS UNIT. 15 



They contain a store of starch, provisions elaborated by 

 tlie plant which produced the seed. On this store of starch 

 the young embryo or infant beech, with its little root and 

 stem, bearing toward its summit the first phyton, or true 

 aerial leaf, is wholly parasitic until it is sufficiently grown 

 to draw a sufficient amount of sustenance from the earth 

 and atmosphere, and can do without the nursing-leaves. 



The polar opposition between root and stem, which is 

 among the first indications of the commencement of active 

 vitality in the young embryo, is wholly inexplicable, and 

 continues throughout the entire life of the tree. During the 

 first stages of its life, oxygen is absorbed from the air by the 

 nursing-leaves of the growing embryo, and through its in- 

 fluence the starch contained in them is transmuted into a 

 soluble sugary gum called dextrine, which is conveyed, by 

 the water absorbed during the germination, to the young 

 rootlet and to the gemmule, and also to the first true 

 aerial leaf, or phyton. Thus nourished, this leaf speedily 

 expands, takes the form peculiar to the plant, and remains 

 permanently attached to them till the close of the grow- 

 ing season. It is otherwise with the nursing-leaves : for 

 having yielded up their store of nutrient material to the 

 first true aerial leaf, and given it the necessary degree of 

 strength to enable it to support itself, they become gradu- 

 ally atrophied, or waste away and shrivel up, and we see 

 them finally fall from the stem. With the full develop- 

 ment of the first true aerial leaf, and the atrophy and ulti- 

 mate fall of the nursing-leaves, the first stage of vegetative 

 life is closed. 



"We have now a simple individual plant, or vegetable 

 unit, consisting of root, stem, and leaf, having subterranean 

 and aerial organs beautifully adapted to its nutrition ; it is, 

 therefore, perfect in all its parts. And now, the fully-de- 

 veloped tree, with its massive stem, branches, and roots, 

 its noble canopy of foliage and flowers, stands before us in 

 its simplest form. For the first true aerial leaf is the 

 foundation of the vegetable fabric, the parent of those 



