834 On the Microscopic and General Characters of (November, 
warfare against the yellows. On the other hand, lack of care in 
cultivation, etc., may reduce the tree to such a condition that it 
becomes susceptible to disease, and is more liable than in the 
first case to catch this troublesome malady. 
Downing says,! “ Let us look for a moment into the history of 
the peach culture in the United States. For almost an hundred 
years after this tree was introduced into this country, it was 
largely cultivated, especially in Virginia, Maryland and New Jer 
sey, as we have already stated, in perfect freedom from such dis- 
ease [the yellows], and with the least possible care. The great 
natural fertility of the soil was unexhausted, and the land occu- 
pied by orchards was seldom or never cropped. Most of the soil 
of the States, however, though at first naturally rich, was light 
and sandy, and in course of time became comparatively exhausted. 
The peach tree, always productive to an excess in this climate, 1m 
the impoverished soil was no longer able to recruit its energies 
by annual growth, and gradually became more and more enfee- 
bled and short lived.” 
I have great regard for the opinion of practical experimenters 
and investigators—the horticulturists of our country—but look- 
ing at the matter from a scientific standpoint, I must confess that 
I firmly believe that if great care be exercised in cultivation, 
pruning, etc., the fruit grower will be greatly aided in reducing 
the spread of this disease. sci 
I can but agree with Professor Kedzie when he says, “T think 
the trees lack potash and phosphoric acid.” These may be ap- 
plied in cultivation by mixing them, either separately or com 
bined, with the earth around the base of the tree where they can 
be absorbed by the roots; or superphosphate of lime and ashes 
may be used. 
The subjects of cultivation and the preservation of th 
and the prevention of this disease by this means, belong 
to the practical investigator than to the microscopist or ch f 
for we, working with our microscope and test-tube, can only ue 
gest and theorize, while the experiments must be left with a ‘5 
who raise the trees. In concluding these remarks, I am eee 
be able to say that many are carefully experimenting and noting 
their observations and results. 
e trees 
rather 
emist, 
1“ Fruits and Frait Trees of America,” eighth edition, p- 464- 
