LEAVES OF OUR HARDY TREES. 193 



THE LEAVES OF OUE HARDY TEEES. 



O. F. BRAND, FARIBAULT. 



Mr. President., ladies and gentUmen: The subject assigned to me is one 

 fit for a book of 500 pages by a Darwin, Gray or G-oodall, and I am com- 

 pelled to say that the best thing about this article as written by me will 

 be its brevity. 



Primarily, the lease of life of any given plant is fixed by the inherited 

 character; secondarily, the lease of life is modified by external in- 

 fluences. Everything that has life must feed upon food, either organic 

 or inorganic, or both. Plants feed largely on inorganic material, al- 

 though the ways by which certain granules under the influence of cer- 

 tain rays of light can cause the dissociation of carbon from oxygen, with 

 which it is combined in carbonic acid, and bring about the formation of 

 an organic substance from materials wholly inorganic, are processes to 

 me entirely unknown. That such processes are being carried on in the 

 leaves of trees during the growing season; there can be no doubt. 



The Great Author of all life gave to such plants as trees, leaf, stem and 

 root, as three general organs, each having its own peculiar function, and 

 although the leaf is a minute thing when compared to the tons of solid 

 matter contained in the stem of one of our large giants of the forest, 

 yet there could never have been a giant tree or tree of any size, whatever, 

 had it not been for the little industrious leaf. I have, heretofore, com- 

 pared the leaves of a tree to so many laboratories, or workshops, having 

 certain well deflned kinds of work each year and each month during the 

 growing season. We understand that the living parts of a tree of the 

 exogenous kind are the rootlets, the buds and leaves and a zone of the 

 newest wood and newest bark. These parts are renewed each year. This 

 annual work of renewal is mainly done by the leaves, and among our very 

 hardy forest trees, such as pine, is mostly accomplished out of inorganic 

 material. We know that in burning a pine tree the ash left is very in- 

 considerable, but represents nearly all that has been taken from the soil; 

 the rest has returned to the atmosphere, from whence it nearly all came. 

 The leaves of our maples, and some other leaves, store up in the tree a 

 good supply of substances easily converted into sugar. Leaves of apple 

 trees have a similar work to do to that done by the maples; they have to 

 make the annual zone of new wood and bark, form buds for the next 

 spring, ripen a crop of apples, and then store up in the tree enough re- 

 serve food material to carry the tree safely through our most trying win- 

 ters. This reserve food is largely starch or sugar, and it seems to me 

 that with a tree of proper cell structure the question of its hardiness or 

 adaptation, then, lies in the ability of the leaf to store up in the tree a 

 proper amount of this reserve food during any and all climatic changes 

 which will environ it in any given country during a long term of years. 



During the past forty years we flnd that among foreign and American 



apple trees introduced here from other parts, there has not been another 



one with a leaf capable of doing the work that has been done by 



the leaves of the Duchess of Oldenburg. At no time during my ex" 



13b 



