58 Von SCHRENK: TEACHING OF VEGETABLE PATHOLOGY 
cryptogams. The time is not far distant, however, when vegeta- 
ble pathology as a separate branch of botanical science will assert 
itself and claim recognition independent of the other branches of 
this science, and when we will have professors of pathology, who | 
will devote their time and attention to this subject alone. At the 
present time the demand for properly trained men to take up work 
in the study of plant diseases is increasing every year, and with 
the rapid development of scientific agriculture, economic questions 
involving the study of plant pathology are becoming more numef- 
ous, and demand more urgent solution. The economic side alone 
will be sufficient to bring about radical changes in the present con- 
dition of this science in our institutions of higher education. 
By vegetable pathology I mean to imply the study of plant 
diseases in its widest sense. It is perhaps not easy to define dis- 
ease accurately, but for our present purposes, it will be sufficient — 
to speak of disease as abnormal physiology, or, as it has been 
termed by Marshall-Ward, “a variation of functions in directions 
which threaten the life of the plant.” 
It is essential that we understand at the outset that we are 
dealing with a living plant and the reactions which its parts show | 
toward environmental conditions. What we are studying are dis- | 
eased //ants, as distinguished from disease-causing factors. This | 
is to be the fundamental conception of this paper. We have bee@ 
studying mildews and rusts long enough, and in so doing made 7 
ourselves believe we were studying pathology, and it is high time 
that it were realized that the patient is after all more important 
than the disease-bringing factor. Assuming that all are agrte 
upon this point, and taking this as a starting-point, let us inquit® 
how we can go about to teach this conception of pathology. It 
is evident that a knowledge of the morphology of fungi will not 
be sufficient, and that a very different method must be adopted 
from the one in vogue in many of our colleges at this time. 
In the first place let me say that we can learn much from the 
kindred science of animal pathology. The study of this subject 5 
generally divided into three groups: (1) Diagnosis, (2) Etiology’ 
(3) Therapeutics. In all cases the living object is first consulted 
then the causal factors, and lastly the remedy. Applying this i : 
plants we find that the symptoms of disease are on the whole not 
