THE TEACHING OF PLANT PATHOLOGY 
. L. H. PAMMEL 
Mr. Chairman : 
I am sorry that Doctor Melhus because of sickness is unable to 
be with you to present the subject of plant pathology from the 
standpoint of a special teacher. I have not had time to get a 
paper ready for you and what I shall say will be entirely informal 
and not necessarily a connected discourse. 
In recent years I have given little attention to the subject of 
plant pathology at Ames, feeling it is in good hands. During my 
early career at Ames I had some experience in giving some train- 
ing to students in this subject. 
Let me say first of all that no one should take up the subject of 
plant pathology unless there is first of all a good fundamental 
training in general botany and related sciences. Opinions may 
differ as to how much of this fundamental work should be given. 
I am inclined to think there should be at least one year’s work of 
five hours per week. This will enable the student to take up the 
general morphology of flowering plants, histology and a brief 
study of lower forms like the algae and fungi. I wish there might 
be added to this general one year course in botany a course dealing 
with the taxonomy of the flowering plants. The student of plant 
pathology should know the common seed plants so that these can 
be identified for the purpose of having a knowledge of the para- 
sitic fungi of our wild plants. It requires a good keen sense of 
wild plants to be able to recognize plants in their juvenile stage 
and many parasitic fungi occur on the young plants. Can 
courses in plant pathology be given in a pedagogical way? I 
think they can. The beginner should learn how to use his ma- 
terial in the best way. First of all it is important to learn some- 
thing about the general character of fungi. A hand lens is in- 
dispensable for the work. Let us say the student has the downy 
mildew of the grape {Plasmopara viticola). The macroscopic 
characters are so evident that the student cannot be led astray. 
The peculiar yellow spot on the upper surface of the leaf and the 
frosty mildew on the lower surface are characteristic. With a 
little practice the student soon will be able to recognize the downy 
mildews. If now the student is familiar with the host plant he 
will have no trouble in placing the fungus in the genus and 
