ON SOME ASPECTS OF VEGETABLE PATHOLOGY 
AND THE CONDITIONS WHICH INFLUENCE THE 
DISSEMINATION OF PLANT DISEASES. 
W. C. STURGIS. 
Tae modern vegetable pathologist finds himself confronted 
at the very outset of his investigations by many preliminary 
questions which he is obliged to answer more or less satis- 
factorily before he can recommend with any degree of certainty 
a definite line of preventive or curative treatment. 
He must be familiar with the main principles of vegetable 
physiology in general and the normal anatomy and histology of 
Whe special plant under consideration, in order that he may 
“ey when and how the general course of the physiological 
activities of the plant is disturbed, and whether the structure 
: 7 he observes is normal or otherwise. In case the anatomy 
‘evidently morbid, he must be prepared to diagnose the case 
"a as great a degree of accuracy as possible. Let us suppose 
a result of extended observations upon one plant or 4 
“ries of plants showing similar symptoms of disease, he finds 
ae enim is generally or constantly associated 
i aa, a I pass over the large class of cases in which 
patho °rganism is observed, and in which therefore the 
— ee put all his knowledge to the test, examine the 
bias, aaa the utmost attention to detail, exhaust all his 
ae ag test every possible theory in his search for opera- 
ee found a possible connection between the dis- 
Ous ecg Mader observation and a living organism, the 
of the Sale of his work begins, viz., the determination 
VEstion Se nus the mere saprophytism of the organism in 
ae it is not enough merely to observe the associa 
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