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the struggle for mastery over the elaborating forces of the plant seemed 
to be decided in favor of the tubers, and when the exhausted and van¬ 
quished flowers yielded their hold upon the superior stems. Had the 
tubers been taken from the ground a week previous to their being 
affected by the rot, they would all have been found, upon careful analy¬ 
sis, to contain the same, or very nearly the same, chemical ingredients. 
Nothing of the rot, at least, could have been predicated of one tuber 
more than another. The disease was unheralded by the approach of 
any external symptoms other than those affecting the vitality of the 
entire plant, and apparently springing from its inherent conditions. The 
tubers in the centre of the hills, attached to the main flower-bearing 
stems, were all, or nearly all, blasted; while the remote ones, those 
attached to the smaller stems, and such as did not exhaust themselves 
by excessive enflorescence, were sound and apparently healthy tubers. 
It seems to be a well attested fact, that there is a strong tendency to 
precocious growth distinguishing the disease ; that in the very act of 
consummating its life—in rallying its vital and material forces to the 
highest point of development—it sinks into putrefaction and death. This 
sudden collapse of the plant, in its powers of assimilation and structu¬ 
ral development; this arrestation of life at the very threshold of vigor, 
is wholly inexplicable upon any theory of gradual exhaustion or inherited 
constitutional weakness, but shows rather an engorged state of the plant, 
a superabundant fullness in its unelaborated juices. The disease would 
appear to be occasioned, then, not by the want of assimilation, but by 
a too crude and imperfect one, arising from the engorged condition, or 
unnatural growth of the plant. 
We are not prepared to say that our views in this respect are entirely 
unsatisfactory, in failing to meet all the difficulties in the case ; but 
from repeated experiments and observations, and a fuller investigation 
of its various phenomena and characteristic features, we are strongly 
disposed to abandon all theories as yet founded upon mere experimental 
results and observations, and regard the disease as a sort of vegetable 
plague, which has already scourged the plant beyond its maximum point, 
and which is now gradually, if not rapidly, decreasing in the severity 
and frequency of its attacks. Plants, as well as animals, have their 
specific forms of disease, those assuming a fixed type and a marked and 
