1NTR OD UCTWN. 11 



REGARDING EXPLANATIONS. 



What has been said regarding the illustrations of 

 apparatus and of results applies, in principle, to the ex 

 planation of physiological observations. As wheat is more 

 valuable than chaff, so is the independent discovery of a 

 principle by the student more valuable to him than its ex- 

 planation by a book or instructor. If the facts to be 

 observed and the principle involved be detailed and ex- 

 plained in advance, the student's power of independent 

 observation and investigation remains undeveloped. 



THE FUNCTION OF THE DEMONSTRATOR. 



It may be well to introduce this topic by a statement 

 of what the function of the demonstrator is not. It cer- 

 tainly is not to rob the student of the pleasure, exhilaration 

 and benefit of the independent investigation of a problem 

 by introducing each laboratory period with an enumeration 

 of the facts and principles which the work of the day is 

 expected to establish. Such an introduction is worse than 

 useless. The desirability of even asking the attention of 

 the entire class to introductory remarks on the general 

 bearing of the problem in hand is to be questioned. If 

 the problem is well chosen and the work in the physiolog- 

 ical laboratory properly coodinated with that in the 

 recitation room and lecture room and that in other de- 

 partments, its significance will at once be evident to the 

 intelligent pupil. If the introductory talk is omitted the 

 prompt student may begin at once, upon entering the 

 laboratory, the problem of the day, and will have a clear 

 gain of ten to twenty minutes. Any supplementary in- 

 struction or' hint may most profitably and ecomically be 

 written upon the blackboard. 



Most of the experiments given in this book cannot con- 

 veniently be performed by one individual working alone. 



