December 30, 1921] 



SCIENCE 



649 



independent action. There is much room for 

 investigation here. We have only a few simple 

 and effective insecticides. Among the inor- 

 ganic compounds, we have the arsenates, the 

 lime and sulphur sprays, and recently the fluo- 

 rides have been coming in. Of the organic 

 substances, we use such plant material as the 

 poisons of hellebore and larkspur, pyrethrum 

 and nicotine; and the cyanides and the petro- 

 leum emulsions are also very extensively used. 

 N'o really synthetic organic substances have 

 come into use. Here is a great field for future 

 work. Some of the after happenings of the war 

 have been the use of the army flame-throwers 

 against the swarms of locusts in the south of 

 France, the experimental use against insects of 

 certain of the war gases, and the use of the 

 aeroplane in reconnoissance in the course of 

 the pink bollworm work along the Eio Grande, 

 in the location of beetle-damaged timber in the 

 forests of the !N"orthwest, and even in the insec- 

 ticidal dusting of dense tree growth in Ohio. 

 The chemists and the entomologists, working 

 cooperatively, have many valuable discoveries 

 yet to make, and they will surely come. 



All this sort of work goes for immediate re- 

 lief. Our studies of natural control follow next. 

 It is fortunately true that there are thou- 

 sands upon thousands of species of insects 

 which live at the expense of those that are 

 inimical to man and which destroy them in 

 vast numbers ; in fact, as a distinguished physi- 

 cist in discussing this topic with me recently 

 said, " If they would quit fighting among them- 

 selves, they would overwhelm the whole verte- 

 brate series." This is in fact one of the most 

 important elements in natural control and is 

 being studied in its many phases by a small but 

 earnest group of workers. 



So far, while we have done some striking 

 things in our efforts at biological control, by 

 importing from one country into another the 

 natural enemies of an injurious species which 

 had itself been accidentally introduced, and 

 while we have in some eases secured relief by 

 variations in farm practise or in farm manage- 

 ment based upon an intimate knowledge of 

 the biology of certain crop pests, we are only 



touching the border of the possibilities of 

 natural control. 



For an understanding of these possibilities, 

 we must await the prosecution of long stud- 

 ies, just as we must await years of progress 

 of those other studies outlined in a previous 

 paragraph. And all of these studies must be 

 carried on by skilled biologists — thousands 

 of them. At present most of the best men 

 are working away in their laboratories prac- 

 tically heedless of the great and inviting 

 lines of study at which I have hinted and 

 heedless of the tremendous necessity for the 

 most intense work by the very best minds on 

 the problem of overcoming and controlling 

 our strongest rivals on this planet. 



And this brings me back to the topic which 

 I touched upon in my opening remarks, namely, 

 the teaching of biology in our colleges and 

 universities. You will remember that I 

 thought to avoid a discussion of this sub- 

 ject because I felt that I could not do it 

 justice without more careful investigation 

 and without a clear knowledge of the view- 

 points and purposes of the educators. A 

 good many of us have been thinking for a 

 long time that the teaching of zoology and 

 botany and the so-called .biology in the 

 principal colleges and universities in the 

 United States and Canada, and in Europe 

 as well, has taken the wrong trend, or that, 

 if not taking the wrong trend, very many 

 of the more important aspects of these sub- 

 jects are being ignored, and that everything 

 was running in a single direction. I said a 

 good many of us. That means that, when 

 we come to count them up, there really have 

 been a good many, but they have been so 

 greatly in the minority that they have been 

 ignored in tlie general movement. Here and 

 there a man has spoken out, but all too in- 

 frequently. Jordan, in his presidential ad- 

 dress before the American Association, was 

 one of these. C. C. Nutting, in two or three 

 papers, has in a forceful and somewhat 

 humorous way pointed out some of the in- 

 consistencies of modern biological training. 

 Edwin Linton, in his strong and fine address 

 at the Baird Memorial meeting in Washing- 



