SUMMER MEETING AT BROOKFIELD. 39 



PRACTICAL HORTIC ULTURE. 



PROF. J. W. CLARK, 



Professor of Horticulture in Missouri Agricultural College. 



Perhaps this paper might better be called facts relating to the 

 growth of trees and plants, for it is with these that the horticulturist 

 has to deal, and the first question that might be asked is, What is a 

 tree, its mission, and how does it perform its work ? Is a tree or a 

 plant simply an individual form, without any regular shape or complex 

 organism in its make-up ? Is it a thing which only happened ! Far 

 from it, for every part — root, stem, leaves, flowers and fruit — is made 

 up of myriads of independent yet dependent parts called cells, carrying 

 the material out of which new growth is formed from cell to cell, by 

 the agency of a minute thread-like structure of this same living ma- 

 terial, which connects the whole living portion of the tree from the end 

 of its tiniest root to the remotest leaf on its topmost branch into one 

 complex structure, working in unison to build up one complete whole, 

 far outvieing the most delicate work of man ; and we have it from 

 Holy Text "that Solomon in all his glory was not arrayed in such gor- 

 geous apparel as clothed the lilies of the field." The mission of a tree 

 or plant is to transform the crude material in the earth and air to a 

 condition suited to use of man and beast. 



^ow where in the tree is all of this life, activity and transforma- 

 tion taking place ? To those who are not acquainted with the manner 

 in which a tree makes growth, the statement that the only part of the 

 trunk and branches of a tree which is alive is the thin layer Of cells 

 lying just between the bark and the wood, with the exception of the 

 few living cells scattered within the bark, may appear fallacious, but it 

 is here that all new growth takes place. The wood beneath which forms 

 the bulk of the tree, and which plays an important part mechanically, 

 by giving strength and furnishing a medium through which the crude 

 sap or solution taken up by the roots is carried to the leaves, is simply 

 a mass of what once was alive, but is now a sepulcher full of the dead. 

 Take the heart of one of the oldest of the mammoth trees of California, 

 if it has not decayed, and we have relics of a past life of greater anti- 

 quity than that which is represented by the mummies of the Pharaoh 

 kings. 



A tree renews itself every year; what was alive last year is now 

 dead aud is hurried by the new growth of the present season, which 



