64 PEOTECTION OF PLA TS — 1923-24 



there will be some differences of opinion as to how this should be achieved. 

 With this type of student it is very little use to give him anything in which he is 

 not interested and which he is not persuaded will be of some advantage to him 

 in his life work. 



One of the difficulties that we have all felt is the necessity of having to 

 use dead and preserved material. It is hard to get enthusiastic over a lot of 

 pickled caterpillars or interested in pinned and mounted flies. It is of the 

 greatest advantage to be able to use at least some living material. In the lesson 

 on mouthparts a live aphis from the green house placed on its back in a drop 

 of Canada balsam with legs and antennae waving in the air and with its beak 

 extending half-way down its abdomen gives a reaction that you can never 

 get from a Cicada taken from a jar of formalin. Aphids, scale insects, etc. can 

 be obtained from greenhouses, some species of leaf -hoppers can be hatched out 

 during the winter months as can many species of moths that hibernate in the 

 egg state. If a greenhouse is available these can be reared and studied there 

 and their work, growth and transformations actually observed. Many animal 

 parasites are, of course, available at this time and can be studied to advantage 

 in the live state. 



Then, since the students are eager for practical instruction a lesson in 

 sprays and spraying should be introduced early in the course, preferably follow- 

 ing that on mouthparts. The actual m.aterials and the actual machinery can 

 be studied at this time. While actual demonstration of their use is diflScult, in 

 fact impossible on a large scale, it is easy to devise a few simple experiments to 

 show that the work is not all "theory" but that it is capable of actual use. If 

 we can get the student to thoroughly appreciate the difference between biting 

 and sucking insects so that they will remember it after they return home, we 

 have done more than even mo'-e advanced courses sometimes do. A simple 

 experiment with some greenhouse aphids and some leaf eating caterpillars per- 

 formed in the greenhouse will demonstrate this in a way that the student will 

 find hard to forget. Then such insects as meal worms, clothes moths, etc. 

 may be studied in the living condition and made the object of simple fumigation 

 experiments. The control of chicken lice or hog lice can also be easily demons- 

 trated in the winter months. Work of this character tends to vitalize our sub- 

 ject and to save it from the "dry rot of academic biology." 



Then to achieve our purpose the presentation of the subj ect should be non- 

 technical. What valid reason can there be to compel the student to master a 

 strange jargon which he cannot and will not use. When a student says he can- 

 not learn any subject because he cannot remember all the long hard names, the 

 instruc+or should endeavor to remove this difficulty from his path as far as it can 

 be done. Why use up all the student's mental energy merely in memorizing 

 technical terms so that he has none left to learn the subject itself? We might 

 as well make up our minds that there is in the mind of the average student — -I 

 mean the average student who takes these com'ses — an ineradicable prejudice 



