THE INNER ORGANIZATION OF TREES. 53 



In a similar manner, the chemical nature of chlorophyl, 

 the substance which gives to the leaves of plants their green, 

 color, has been examined; so also, gum, sugar, resin, and the 

 other products of the cells. It has been ascertained that 

 starch passes into dextrin and sugar, which substances are 

 again transmuted into starch ; but when we look at the rich 

 diversity of vegetable productions and find that the most 

 learned Chemists and Physiologists are compelled, through 

 pure ignorance, to speak in the most general terms about the 

 nature and order of these changes, we cannot but feel how 

 little the works of Nature are understood. Look at the 

 flowers in any garden I What an endless variety of color, 

 form, and fragrance ! Each variety of leaf connected with 

 the stem, including the pistils, stamens, petals, sepals, and 

 even the bracts, stipules, and bud-scales, are doubtless formed 

 with an especial reference to the elaboration of the sap into 

 those final products by which the plant is characterized ; yet, 

 notwithstanding all that has been written and said on the 

 subject, it must be confessed that we cannot, as yet, appreci- 

 ate the perfection of the machinery, or trace the progress of 

 the raw material through all its changes, until it reaches its 

 final metamorphosis. In this respect, not only the tree, but 

 the commonest weed is an interesting study; it exemplifies 

 the laws of growth quite as much as the costly exotic in the 

 conservatory. The flowers and forest trees which cover and 

 adorn the earth may be regarded as so many beautiful 

 living problems, which are everywhere presented to us by 

 the GREAT INTELLIGENCE for our solution. 



And now, reader, may I be permitted to lay before you 

 some reflections which appear to me to be suggested by the 

 facts advanced in the last two Chapters. 



Be usefully employed, never be idle. This grand moral 

 lesson is taught us by every portion of the fabric of a tree. 

 Not only each goodly branch and vigorous shoot, each frail 

 and perishable leaf of the many thousands which have 

 passed forever away, but even the minutest and most insig- 

 nificant bract and bud-scale has contributed to the formation 



