power; by this I do not mean that the
roots are diseased, but that they are either in an aberrant or abnormal
state; but disease cannot be predicated upon either of these states. To
explain: everybody knows _Spirea callosa_ to be a strong growing shrub,
having umbels of rosy-colored flowers and strong, stout roots; the white
flowered variety is quite dwarf, is more leafy and bushy than the
species, and has more fibrous and delicate roots than the type; the
crisp-leaved variety is still more dwarf, very bushy, and very leafy,
and has very fine threadlike roots. This would indicate that the
aberrance is in the roots; the two varieties are much more leafy in
proportion to their size than the species, so that if the leaves
controlled the roots, the latter should have been larger in proportion
than those of the species. Again, once when, in the autumn, I was
preparing my greenhouse plants for their winter quarters, I cut back a
"Lady Plymouth" geranium, which chanced to be set away in a cool and
somewhat damp cellar. When discovered the following February and started
into growth in the greenhouse it produced nothing but solid green
leaves, and never afterward produced a variegated leaf. This I
attributed to its having gained greater root power during its long
season of rest. By this I mean that the roots had grown and greatly
increased in size, although there had not been any leaf growth. That
roots under certain circumstances do so is well known. The roots of fir
trees have been found alive and growing forty five years after the
trunks were felled. The same has occurred in an ash tree after its trunk
had been sawn off level with the ground. A root of _Ipomea sellowii_ has
been known to keep on growing for twelve years after its top had been
destroyed by frost; and in all that time it never made buds or leaves,
yet it increased to seven times its original weight. The tuberous roots
of some of the _Tropoeolums_ will continue to grow and increase in
size after the tops have been accidentally broken off; and potatoes
buried so deep in the earth that they cannot produce tops will produce a
crop of new potatoes.

On the other hand, I have had an oak-leaved geranium overlooked in a
corner of the greenhouse until it was almost dried up for lack of water.
When its branches were pruned back and it was started into growth only
one branch showed the almost black center of the leaf, all the rest were
clear green. This was an evident ca