8 PLANT PHYSIOLOGY. 



courses, and the use of the simple appliances will make it 

 equally practicable, as it certainly is equally profitable, in 

 physiology. 



Very important in such a course as this is the proportioning 

 of its topics. The course should aim to give a knowledge not 

 only of the leading physiological facts, but also of the relative 

 importance of those facts in moulding the plant kingdom as it 

 is. Consequently, important topics should receive due atten- 

 tion and experimentation, even though this may be difficult 

 and expensive; and in cases where, as in many chemical ques- 

 tions, no experimentation at all is practicable, the topics should 

 nevertheless be introduced with due emphasis into their proper 

 places in the scheme and given book- and lecture-study. Such 

 non-practical study of occasional topics closely yoked to topics 

 practically studied, is vastly better than no study of them at 

 all. On the other hand, in the case of some topics of minor 

 value, many simple and beautiful experiments are available, 

 and the temptation to dwell upon and use many of these must 

 be resisted, only enough being chosen to emphasize the topic 

 in its true proportions. It is chiefly by the amount of em- 

 phasis laid upon them in the outline and lectures of his course 

 that the student infers the relative importance of the parts of 

 his subject. The worth of a physiological practicum, there- 

 fore, is by no means to be judged alone from its number of 

 practicable and logical experiments, but rather by the degree 

 of truthfulness with which it reflects to the mind of the student 

 the true proportions of the entire subject. 



We have next to consider what position such a course may 

 best hold in a college curriculum. Theoretically it should 

 come as early as possible, even preceding the study of struc- 

 ture, on which it throws a flood of light. But, as every teacher 

 knows, what is fairest in theory often plays false in practice. 

 The facts and phenomena with which physiology deals are of 

 so unfamiliar and abstract a sort that the student must have a 

 large foundation in concrete facts before he is prepared to grasp 

 their real significance and value. A good guide in such cases 



