402 



SCIENCE 



[N. S. Vol. XL. No. 1029 



of these was the obvious fact that the raising 

 of crops is essentially nothing more or less 

 than applied botany. The botany which is 

 useful in plant industry is not a study of the 

 names of cultivated plants and weeds, and not 

 primarily the cataloguing of plant products 

 and plant diseases, but is the phase of botany 

 which treats of the responses of plants to the 

 conditions under which they grow. This is 

 plant physiology. It is a phase of botany 

 which can not be taught to students who have 

 not some previous general knowledge of 

 plants. It is here taught to students who have 

 had one year of general botany, but who have 

 not yet any chemistry. Some have had phys- 

 ics and some have not. It would be impos- 

 sible to give to our students the sort of a 

 quasi-cultural subject which is usually pre- 

 sented where plant physiology is taught at all 

 in the United States. But a considerable 

 part of the American course which could not 

 be given to our students would likewise be 

 useless to them. Our course in plant physiol- 

 ogy is planned specifically to give students 

 such an understanding of the behavior of 

 plants as should serve as a guide in the treat- 

 ment of crops. 



This course was put in operation here with- 

 out any advertising; while I felt perfectly 

 sure that the proposition that the best scien- 

 tific foundation for plant industry is a knowl- 

 edge of plant physiology, is a sound one, I 

 felt also that the general respect for a widely 

 adopted system would be so strong that a rad- 

 ical experiment of this kind would be sure to 

 receive very little favorable attention until it 

 had been well tested in practise. Five years' 

 experience should be enough to put a plan, 

 which may have looked like an experiment at 

 its first trial, on a different basis. During 

 these five years, the same plan in greater 

 dilution has been applied in some places in the 

 United States. The example of Wisconsin in 

 requiring half a year of plant physiology of 

 students in some agricultural courses may have 

 more weight in commending the subject than 

 does our local experience with a full year. 

 The desirable thing is that the value of the 

 subject be recognized, and it is to be hoped 



that Wisconsin's example will be followed by 

 other institutions as fast as is in their power. 



It has already been stated that our course 

 in physiology is fitted directly to the practical 

 purpose it is to serve. For this purpose, 

 growth receives particularly careful study. 

 The student is drilled in grov?th measure- 

 ments until he regards them as a matter of 

 course, rather than as experiments. The num- 

 ber of such measurements required of each 

 student is approximately 3,000. Aside from 

 giving a thorough first-hand idea of the growth 

 of a variety of plants and of different parts of 

 plants under various treatment, this extensive 

 drill has the practical result that the student 

 acquires speed and accuracy in such work, 

 such that if he is afterward called upon to de- 

 termine how fast the plants in a corn field or 

 coconut or coffee plantation are growing, he 

 goes at it with skill and confidence. I have 

 asked a number of graduates of American 

 agricultural colleges how fast corn should 

 grow at different ages; not one could give 

 anything better than a relative and altogether 

 indefinite answer. Not one of them knew 

 anything about it from personal observation 

 of a single plant. Not one had, so far as he 

 remembered, even been given a figure on the 

 subject; let alone being called upon to fix it 

 in his mind by finding out for himself. Not 

 one had any standard by which he could state 

 that a plant or a field of corn was growing as it 

 should, or doing better or worse. It seems to 

 me that the graduate of an agricultural college 

 should know a good deal more about the be- 

 havior of corn than any of these graduates do 

 know. It would amaze our students if they 

 were made to realize that a student could grad- 

 uate from a famous agricultural college in a 

 state where corn is a leading crop, without 

 ever following through the grovrth of a single 

 corn plant. Com has received a careful study 

 of just this kind in the United States, and is, 

 so far as I know, the only American crop 

 which has received a really careful study of 

 this kind. 



Next after growth in the attention it re- 

 ceives is transpiration. Next in order is di- 

 rect study of the mineral food of plants, and 



