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SCIENCE 



[N. S. Vol. XXXIX. No. 1002 



guide or previous training is not an easy- 

 task for the older teacher. Here is per- 

 haps the point in the new work at which 

 the young and the would-be-young are most 

 clearly differentiated. To me the contem- 

 plation of this subject is embarrassing and 

 I pass it by. But for the encouragement 

 of those who are in my plight, I must add 

 a word from my own experience. 



I believe that some of us who are older 

 teachers fail to appreciate, from our disin- 

 clination to give the matter a trial, how 

 easy it is to arrange elementary courses, 

 especially the laboratory exercises in such 

 courses so as to illustrate animal activities 

 by the experimental method. I know that 

 in my own experience a laboratory course 

 which I gave to high-school teachers a year 

 or so ago was in this respect immensely 

 illuminating. I had no idea that the new 

 methods could be applied so directly. To 

 give some notion of the nature of the work 

 that can be carried on in such courses let 

 me name some of the exercises that we 

 found serviceable: the effects of light on 

 the movements of planarians, earthworms, 

 mealworms and the larvffi and adults of 

 flesh-flies; the combined influences of 

 gravity and light on the movements of 

 fruit-flies ; the effects of odorous substances 

 on the movements of earthworms and on 

 the gathering of fruit-flies ; the feeding re- 

 actions of planarians, catfishes and toads; 

 the means of locomotion in earthworms, 

 mealworms and snails; the reactions to 

 stimulation in paramsecium, and its rate of 

 reproduction ; regeneration in planarians 

 and earthworms; heredity in fruit-flies. 

 These and other like exercises were found 

 surprisingly applicable to elementary work 

 and have encouraged me to believe that 

 practise in experimental work may well be 

 introduced into elementary courses. 



Such work, moreover, is not without its 

 beneficial influence on the teacher. No two 



animals are ever alike in their reactions, 

 and in this respect they differ vastly more 

 than they do in their structure. Although 

 each exercise can be made to lead to a gen- 

 eral conclusion for all students concerned, 

 the details of the work soon come to be 

 individual. The instructor is called upon, 

 therefore, rather as an adviser in method 

 than an authority in facts, and from this 

 standpoint his attitude toward his work is 

 much more natural than what it often is 

 in purely anatomical exercises. Woe be to 

 him if he begins to tell what a given animal 

 at a given moment will do ! I know of no 

 elementary biological exercises that are bet- 

 ter adapted than these to develop inde- 

 pendence and originality in the student 

 and to reduce the instructor to his true 

 position, that of a student of greater matur- 

 ity than those about him. As a result of 

 this experience, I look with great hope on 

 the steady introduction of experimental 

 exercises into our elementary work. Cer- 

 tainly the conception of an animal that is 

 gained from work such as this is much 

 nearer the truth than that which we have 

 been instilling through alcoholic specimens. 

 But if these are the realities of the ex- 

 perimental method, what are its vanities? 

 I think the chief pitfall that besets the 

 experimentalist is apparatus. What a 

 strange allurement this feature of the situ- 

 ation has for us ! What can be more pleas- 

 ant to the eye than beautiful apparatus in 

 glass eases or a grand array of delicate con- 

 trivances built up upon a table ! And they 

 are always so interesting to the visitor! 

 But I shall never forget the comment of a 

 friend of mine who on looking over an ex- 

 tensive device of my own construction 

 finally remarked that the justification of 

 such work as biological did require a goodly 

 supply of brass. But if apparatus is our 

 pitfall, we must remember that many of 

 the pioneers in the new movement have 



