CHAPTER IX. 



CHANGE WHICH TAKES PLACE IN THE CONSTITUTION OF 

 TREES AT THE PERIOD OF PUBERTY, ORGANIC METAMOR- 

 PHOSIS OF THEIR LEAVES INTO FLOWERS AND FRUIT, 

 AND RELATIVE PHYSIOLOGICAL RANK OF THE FLORAL 



ORGANS. 



HITHERTO our remarks have been confined entirely to the 

 vegetative stages in the development of the tree ; and therein 

 we have endeavored to point out the interesting fact, that it 

 is a plant of a highly compound nature, built up by the labors 

 of simple individual plants or phytons, commonly called leaves. 

 At first a certain number of these leaves associated together 

 form individual plants of a higher order called shoots ; then 

 these shoots, by reproduction and association of themselves, 

 produce in the same manner plants still more highly com- 

 pound, called shoot families ; next, these families of shoots, 

 developing about a common axis, form branches, and finally 

 these branches unite together in one common trunk, and thus 

 construct the one individual Tree, which is therefore the last 

 and most highly compound plant in the series, and the noble 

 descendant of an unbroken line of ancestors, of which the 

 first phyton or leaf, nourished to maturity by the nursing 

 leaves, was the lowly but illustrious parent. 



Now, among the numberless shoots and branches of a tree, 

 a great many retain, through all the stages of its life, their 

 purely vegetative character; and their phytons or leaves, 

 without ever experiencing any further metamorphosis, oscil- 

 late forever between the two opposite conditions of leaves 

 and bud scales. The leaves of the remainder, however, are 

 carried forward to the highest stage of vegetable metamor- 

 'phosis, that of flowers and fruit. This takes place generally 

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