148 TEANSACTIONS OF THE ILLINOIS 



assinutation — a very different thing from the assimilation of food 

 by animals. In plants this name applies to the process of con- 

 verting inorganic elements into organic compounds. Ordinary 

 chemical processes uniformly degrade and tear down, but here is the 

 one, and the only one, natural method of building up, of combining 

 simpler compounds into one more complex, of making out of incom- 

 bustible and non-nutritious elements combustible products and food 

 for all living things. Let us repeat, this is the work of the green 

 parts of plants. Roots have no power in this respect. They help 

 furnish the materials, the leaves elaborate these and send the pro- 

 ducts in part back to the roots for their sustenance. No manures 

 or fertilizers of any kind can be absorbed by roots and directly used 

 as food by them. Persons have been known to apply manures to 

 asparagus beds in early spring for the purpose of making, that 

 season, the edible roots stronger and more rapid in growth; of course 

 a mistake, so far as food supply is concerned. A farmer once said to 

 the writer: " I do not think the potato bugs will do much harm, they 

 only eat the leaves; the potatoes will develop all right, because the 

 roots, are not hurt." He knew better after a few weeks. 



Practical Snggestions. — The lessons drawn from the foregoing 

 in regard to transplanting trees are too obvious for much discussion. 

 When one realizes how extensive normal roots are, he will be likely 

 to take more pains in digging to secure as many as possible. When 

 it is understood that the youngest root fibers are preeminently the ac- 

 tive ones, these will be saved as far as practicable, both in the manner 

 of digging and in the care against fatal exposure. As most roots 

 start into new growth before the buds swell, the importance of early 

 transplanting will be recognized. 



Among horticulturists there is much difference of opinion as to 

 the effect of grafting apple scions on pieces of roots rather than 

 upon a whole stock. One says in the latter method, the taproot is 

 preserved, while it is destroyed in the first proceedure, and the whole 

 life of the tree is thereby modified. When we know that a lateral 

 branch takes the place of a destroyed primary, nothing is left of this 

 assumption, though great business operations are still dominated by 

 the false idea. Another sees a vital part in what is called the " col- 

 lar" of a tree, the juncture of the stem and root. This collar, it is 

 asserted, has no existence in the ordinary root-grafted tree. The 

 idea is one of pure conjecture and groundless speculation. 



The knowledge of the widespreading of roots will dictate some- 

 thing as to distance apart for various plants. If grapevines, in two 

 years, even under special circumstances, send roots out thirteen feet 

 from the stem, some consideration of this fact will be given in de- 

 termining how far distant the vines shall be in a vineyard. If wheat 

 fills the soil with masses of roots, may not studies upon these help 

 in determining how much seed to the acre should be sown? 



