Chap. IV.] 
MISCELLANEOUS. 
139 
other. This may be observed in the natural 
spiral carved work, formed by woodbine on the 
stems of coppice-wood; and doubtless, if instead 
of the woodbine wire were placed spirally up 
the stems, very regular and beautiful patterns 
might be produced. Wire fences, fixed on the 
stems of trees, destroy the circulation and kill 
the sides of the trees on which they are fixed. 
Again, as far as I have remarked, though 
young roots are round, the older ones greatly 
incline to the oval shape; and in all the trans¬ 
verse sections of roots which I have examined 
the eccentricity of the common point from which 
the ( medullary ?) rays diverge, and which is 
occasioned by the comparatively over-growth of 
the upper sides of the new annual rings, is very 
striking. I imagine that this is caused mechani¬ 
cally , and that it is the result of the growth in 
girthing of the roots meeting with less mecha¬ 
nical resistance from the earth on the upper 
sides. 
As long as a branch-root exists, it must, 
owing to its lateral growth in girthing, annually 
approach the surface of the ground, and, after 
that is reached, ascend above the surface. 
Suppose a root to run horizontally at the depth 
of one foot below the surface of the earth. Sup- 
one side of the 
stem to the 
other. 
Lateral upward 
growth of the 
root. 
