PREFACE. V 



It may be well to anticipate a possible objection. A few 

 persons, some of them worthy of respect, assert that no ex- 

 periments on an animal can be shown to a class without 

 hardening the hearts of operator and spectators ; even when, 

 in accordance with the directions given in the following 

 pages, the animal is anaesthetised and while in that condi- 

 tion is killed or its brain destroyed. This from an experi- 

 ence of more than fifteen years in the teaching of practical 

 physiology, I know to be not so. So far as the experiments 

 described in the present book are concerned, their effect is 

 most certainly humanizing. Young people are apt to be, 

 not callous, but thoughtless as to the infliction of pain. 

 When they see their teacher take trouble to kill even a frog 

 painlessly, they have brought to their attention in a way 

 sure to impress them, the fact that the susceptibility of the 

 lower animals to pain is a reality, and its infliction some- 

 thing to be avoided whenever possible. 



As the question of size is no unimportant one in 

 relation to textbooks designed for junior students with 

 many other subjects to learn, I may be permitted to say that 

 though this volume contains more pages than most of those 

 with which it will have to compete, I believe it is not really 

 larger The extra pages are due, in part to the above- 

 mentioned appendices to the chapters, and in part to the 

 great number and large size of the figures. My publishers 

 had on hand electrotypes of the figures of the octavo edi- 

 tion, and have been able to utilize them in illustrating this 

 briefer one much better than most textbooks of its scope, 

 without proportionately increasing its price. 



If I had relied solely on my own judgment the ques- 

 tions at the foot of each page would have been omitted. But 

 it was strongly represented to me by those whose opinion 

 I had reason to value, that such questions were useful 

 in enabling a student to test whether he had mastered his 

 lesson, and that teachers who disliked such prearranged 

 questions could and would ignore them. I hope that 



