PREFACE TO THE THIRD EDITION 



The last thirty years have been very productive of text- 

 books of Zoology, both for secondary schools and for colleges. 

 Many of these are admirable from the point of view of the science 

 itself. It has become increasingly apparent, however, that the 

 right text-book of Zoology, as of every other subject, is primarily 

 a matter of psychology. The prime object of all teaching is so 

 to use the subject as to produce the best possible result in the 

 personality of the pupil. Tljiis means that the mental structure 

 and functioning of the pupils are even more important than the 

 subject matter in conditioning the presentation of any subject. 

 Teachableness is the first prerequisite in any text-book in any 

 subject whatsoever. During the last ten years the writers of 

 our text-books have shown an increasing appreciation of this. 

 Nevertheless it is still true that some of the best zoologies we 

 have from the point of view of the science of Zoology are peda- 

 gogically impracticable. 



It is the purpose of the present book, however much it may 

 fall short of its aim, to subordinate certain zoological prepos- 

 sessions to the mental requirements of freshmen. The method 

 here adopted has been used successfully by the writer in a first 

 course, for more than twenty years. It has secured good interest 

 and fine spirit. The following are some of the principles that 

 have guided him in the selection and arrangement of the mate- 

 rial in the present volume : 



I. The work done in a first course is primarily for pupils 

 who do not take a second course. This first course should be 

 handled, therefore, as a life-training rather than as satisfying 

 a college requirement. It should seek to accomplish these, 

 among other, things: 



The production and conservation of a vital interest in 

 animals ; an appreciation of the human values of animals ; 

 the encouragement of the attitude of raising and solving 

 problems concerning animals; some ability to use the 

 library, the field, and the laboratory in individual pursuit 

 of these interests; the ability to sustain interest in these 



