369 
mg, by the particles of decaying vegetable matter adhering to them, & 
small supply of food, besides protecting the tender root from the action 
of the sun. The roots less favorably situated on the top of the wail, 
are affected by drought early in summer, and cease to lengthen ; and 
the conditions are not favorable to the emission of lateral fibres from 
the roots proceeding dowm the side of the rock. The plant thus be¬ 
comes dependent on that one root chiefly for its subsistence, and its 
growth is rapid compared with others. 
Roots must have access to atmospheric air. “Under natural circum¬ 
stances,” Lindley observes, “the tendency of the roots to keep near the 
surface is invincible.” An acquaintance brought to him a Lucerne root 
eighteen feet long, in proof of the common opinion that they go deeply 
into the soil, and may be buried deeply with impunity. On investigation 
it was found that the root had proceeded down the side of a gravel pit, 
and was never more than six inches from the surface. “ The celebrated 
Duhamel,” says Col. Greenwood, “wishing to protect his field from rob¬ 
bery from the roots of a row of elms, cut a deep ditch between the elms 
and his fields. The roots however were not to be done. They of course 
followed the surface of the ground, whether down, horizontal, or up hill, 
and took the ditch in and out clever into the philosopher’s field. Duhame| 
thinks they were cunning roots, and that they had an instinctive notion 
of the treat they were to have on the other side of the ditch, and grew 
at it. Had the philosopher built a wall in the ditch and then filled it in, 
he would have beaten the roots, on account of their inability to leave the 
surface and get under the wall.” By studying these facts we may un¬ 
derstand some of the reasons why deep plowing, enriching and pulver¬ 
izing the soil, and relieving it of stagnant water by means of draining 
prove so beneficial. 
Leaves are most important organs, and their use in the economy 0 £ 
vegetation should be well understood by all who cultivate plants. Every 
part of the plant is considered to be composed of matter which has been, 
previously elaborated or prepared by mature leaves; hence, it has become 
an axiom with the more intelligent gardeners of the present day that 
the product of a plant will, all other circumstances being similar, be in 
direct proportion to the extent of healthy foliage which it can expose t& 
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