viii PREFACE 



to see any pedagogical difference between directions and explanations written 

 in the manual and those given out verbally by the instructor, but I do see a great 

 deal of difference as concerns the time,' patience, and energy of instructors and 

 students. Our experience with laboratory manuals of the type in which the 

 burden of discovery is left to the student is that the student becomes highly 

 dissatisfied and that the instructors are brought into a state of irritation and 

 fatigue by the continuous demands for assistance with which they are bombarded. 

 Frankly, I believe in the conservation of instructors, and have written this manual 

 with that end in view. In place of inserting questions in the laboratory manual 

 our method is to hold thorough oral quizzes on the laboratory and textbook work 

 at frequent intervals. 



Although a number of drawings are called for in the manual, it is probable 

 that each instructor will prefer to decide for himself what drawings are to be 

 made. Drawings might profitably be omitted altogether, their place being 

 taken by rigorous practical individual quizzes on the dissected specimen. 



I am indebted to a number of authors and publishers for permission to 

 reproduce figures from their publications. Due acknowledgment is made in 

 the legends to these figures. I have not listed the numerous original papers to 

 which I have referred, since most of them are given in the bibliographies appended 

 to Kingsley's Comparative Anatomy of Vertebrates and Goodrich's account of the 

 fishes in Part IX, first fascicle, of Lankester's A Treatise on Zoology. I am in- 

 debted to Dr. C. R. Moore, Dr. B. H. Willier, and Dr. J. W. Buchanan for calling 

 my attention to errors and omissions in the first draft of the manual which has 

 been used in the laboratory under their direction during the past two years. 

 My thanks are also due to Mr Kenj'i Toda for his patience and skill in drawing 

 the illustrations. Finally, I wish to acknowledge the fact that the previous 

 organization of the laboratory work along comparative lines, chiefly through 

 the efforts of Dr. J. W. MacArthur and Mr. J. G. Sinclair, has facilitated the 

 task of preparing this manual. 



So laborious has been this task and so great is the number of facts to be con- 

 sidered that I can scarcely hope to have avoided errors, omissions, and state- 

 ments lacking in clarity. I shall be more than grateful to have my attention 

 called to them. 



University op Chicago 

 November, 19 21 



