Chap. IV.] 
MISCELLANEOUS. 
145 
Such a tree, in the form of its stem and root 
together, should resemble two carrots placed 
head to head, or two cones with their bases one 
on the other. It should have no spurs whatever, 
or swell of the roots; but, on the contrary, 
should immediately decrease below the earth. 
We will say nothing of the mechanical difficulty 
of boring (with a sponge ) through the solid 
deposits at the depth of 100 ft. from the surface 
in the longitudinal growth of the root, or of 
what the sponge, or the one capillary stoma , is to 
get there in the way of chemical nutriment; but 
to enable this monster carrot to increase laterally 
at these depths would require a force indeed re¬ 
sistless,—a force equal to that of igneous action, 
—a force sufficient to cleave the world asunder. 
In whatever light we view the idea of a tap-root, 
except for the seedling, it appears to me so 
preposterous that I think we may at least throw 
the onus probandi on the assertors of the 
positive, and say, “ If there be such a thing as a 
tap-root, find one, and show it to us.” 
Nay, I am so easily contented that I shall be 
satisfied of the existence of a tap-root, if a large 
oak can be shown without the large spurs indi¬ 
mentions it as distinct from the quercus, in the beginning of 
the second book of the Georgies. 
L 
A tap-rooted 
tree should have 
no spurs or 
swell of the 
roots. 
