vi PREFACE 



demonstration however skilfully conducted. Indeed, paradoxical though 

 it may sound, the more skilfully a demonstration experiment is performed 

 the less from it do some students learn. 



The course as arranged here has taken shape gradually under experience 

 during the endeavour to devise the kind of teaching needed. It has come to 

 comprise twenty-one lessons, each consisting of somewhat less than three 

 hours' work. On the twenty-four lesson cycle as followed in this University, 

 three class-meetings remain over for repetition of such particular items as the 

 student may want to revise before examination. 



To the student's directions for each exercise is subjoined a short 

 annotation concerning the source and bearings of some of the more salient 

 obsei-vations included in the Exercise. If in these remarks the trend is 

 often historical, it is because that approach has seemed to enable the student 

 best to assess for himself the intellectual cost and value of the observations 

 he is repeating. 



The illustrations supplied both in the plates and text-figures have all 

 been drawn from preparations and apparatus as used in the class. The 

 graphic records reproduced have been obtained by the class-students them- 

 selves. At the end of the volume an Appendix contains suggestions as to 

 methods of arrangement and preparation for the class based on experience 

 of its actual working. 



The interest uniformly shown by the class-students has furnished evidence 

 welcome to me that the course in their eyes possesses real utility. In many 

 instances a fresh impulse seemed to have been imparted to their physiological 

 study. The class-work has cei*tainly vivified for them the reading of the 

 systematic texts. 



I am not so sanguine as to suppose that the choice of method or the 

 selection of object which I have adopted will always appeal to others as the 

 best. Nor can I hope to have escaped, in a venture like the present, all 

 errors of omission or commission. I- would, however, say that I have been 

 at pains throughout to choose the suitable and to describe it correctly. As 

 it is, the course and its syllabus have been cited with approval in a Memo- 

 randum issued by the Board of Education last year. Sir George Newman 



