136 MISSOURI STATE HORTICULTURAL SOCIETY. 



The tree's structure is the bark. First the liber or fibrous bark, that 

 is, their inner bark. Second, the green bark, which contains he same 

 matter as the leaves, and is covered during the year with. Third, a 

 corky layer, whicli is the same as the cork now in use. Fourth, the 

 epidermis or skin which covers the whole. The whole of the growth is 

 made from this inner bark. Next to it comes the sap-wood, the grow- 

 ing part of a tree, and a layer is put on every year on the outer side 

 under the bark. Then the heart-wood which has changed color and 

 has little to do with the life of the tree. 



The living parts of a tree are : First, the rootlets, at one extremity ; 

 second, the buds and leaves of the season on the other ; and, third, the 

 newest wood and the newest bark of the body. The new growth be- 

 tween the wood and bark is called the cambrian layer, and is so tender 

 that the least effort will raise the bark. But this is all composed of 

 cells, so young that it looks like mucilage, but the cells forming so 

 rapidly by division that a person becomes bewildered. 



The leaves consist of the woody parts (ribs), and cellular part, 

 these cells being filled with the chlorophyl (that is, the green of the 

 leaves). The upper part close and glossy to shed the rain, the lower 

 part porus and open for the work of the tree, the breathing apparatus. 



The trees and plants are, as before intimated, using up the carbonic 

 acid and giving out ogygen, while animals are using ogygen and ex- 

 haling the carbonic acid. Thus the growth of the plants are a medium 

 by which such matters are kept evenly balanced. What this life is, 

 just how it does its work, why it will take from the same soil the same 

 particles and [produce the apple, or the peach, or the grape, or the 

 strawberry, we can not tell, no more than we can tell why the same 

 grass will produce the hair on the horse, the wool on the sheep and the 

 feathers on the goose. And this problem will never be solved why 

 this same life principle, protoplasm, which we can not tell whether it 

 will produce apple, peach, grape, strawberry, horse, sheep or goose, will 

 if under the proper conditions do so. God only knows these things, 

 and His goodness and wisdom rules them all. 



The paper lead to a spirited discussion relative to the changing of 

 growth buds to fruit buds by girdling or otherwise injuring the tree. 



