practical papers—fire blight. 
403 
sues, the presumption is that they are the consequence and not the 
cause of this disorganization.” 
P. J. Berkmans, of Augusta, Gfa., in 1860, reasons very clearly 
upon the cause of blight. Starting from the fact that a tree is an 
organized body, with its cellular tissue as the basis of its organi¬ 
zation ; performing its functions of absorption and circulation 
upon the same principle as the animal life, any sudden interfer¬ 
ence with these functions, from overfeeding, starvation or other 
causes, disease or death is produced. 
The writer then shows blight, as accompanying periods of 
excessive growth, to be the result of a sudden distension of these 
cells, or sap vessels, causing inward rupture, or a hemorrhage of 
the vegetable blood, and destruction of the tissues of certain por¬ 
tions of the tree. His remedy is to provide artificial outlets for 
the superabundant sap, by longitudinal incisions upon the trunk 
and limbs of the tree. Seven years subsequently, the same writer 
says his theory proves substantially correct, and his remedy suc¬ 
cessful, and concludes an article on this subject, as follows : “ Fun¬ 
gus may be the cause of blight, but my observations are that it is 
always brought after the blight, as nature will always bring forth 
destroying parasites as soon as life is extinct in a plant. Although 
my observations have been *close, I have never observed any 
fungi before the appearance of blight, but often afterwards.” 
These condensed notes of the writings of some of our most 
earnest students of vegetable physiology, show the drift of their 
opinions, and their theories upon this disease. I do not consider 
it necessary to criticise these several theories, nor do I condemn 
any of them as unworthy of careful attention, which an earnest 
student cannot give without exploring a wide field of thought in 
the science of vegetable physiology. So long ago as 1860, I took 
the ground on sbme propositions made for the consideration of the 
Northern Ill. State Horticultural Society, that the presence of fungi 
in diseased trees was not a cause, but a consequent, and that they 
do not seek healthy, organized matter as their food, but that they 
are the universal scavengers, which seek out effete matter, to 
transform which into a lower order of existence is their work. 
With the same views now, I cannot but regard all efforts to their 
