32 
THE FOOD OF TREES IS IMBIBED [Part II. 
Form of the 
root a flat cir¬ 
cle, like a 
wheel; form 
of the head a 
globular circle, 
like a ball. 
side it, there is every reason to believe that more 
falls there. 
In reference to the comparative length of the 
roots and branches, there is doubtless great dif¬ 
ference in different trees. But generally it is 
probable that the aggregate bulk of timber in 
the root, is equal to that of the trunk and head ; 
and as the roots creep along the surface of the 
earth, they form a flat circle, like a wheel round 
a single tree, instead of a spherical circle like 
a ball as the head does. Consequently, the 
roots make up by their horizontal length for 
their want of opportunity to shoot perpendicu¬ 
larly either upward or downward. Those who 
will not trouble themselves to dig for this truth, 
may see it in trees which are apt to throw up 
suckers, such as the elm or aspen. Suckers may 
be seen from these at four, or perhaps I might 
say at eight or ten, times the distance of the length 
of the branches from the trunk; and were we to 
imagine that part of the head of a tree which is 
above the lowest tier of branches taken off, and 
added to the ends of the lowest tier, so as to 
form a circle in one plane like a wheel, instead 
of a spherical circle like a ball, we should not 
have a bad idea of the general shape of the root, 
both in form and extent of circumference. Con- 
