4 PREFACE. 



written fipin a pedagogical standpoint, and is intended to point out 

 so carefully the content of the subject, and to indicate so clearly 

 a method by which the content may be realized, that no teacher 

 and no pupil who follows the plan here indicated can fail to 

 realize a large part of the value to be derived from the study of 

 elementary zoology. 



There are at least three stages in the study of zoology. First, , 

 the one in which the student learns how to study and how to utilize 

 zoological material. Knowledge of facts is a very subordinate aim 

 in this stage, and the method of acquiring knowledge is very im- 

 portant. This is the stage of greatest educational value, and is but 

 little transcended in high school work. It is the introductory stage, 

 and justifies the name of Introduction for this book. The second 

 stage is the one in which knowledge of facts is the chief end sought. 

 It is essentially a reading stage. The student must read every- 

 thing about the subject, or that part of the subject to which he 

 turns his attention. The third stage is one in which the student 

 undertakes original investigation and adds to the world's stock of 

 knowledge. 



This analysis shows us that the work of the introductory stage 

 must be largely laboratory work. The writer fails to see how very 

 much good can be obtained from the study of a science that is not 

 pursued in this way. Even the reading of books is not to be rec- 

 ommended, unless they deal with phases of the subject that are 

 not investigated in the laboratory , although in a few instances it 

 has seemed impracticable to avoid giving some information in the 

 text that might be derived from the study of the specimen itself. 



In this book it is intended to combine the advantages of Natural 

 History study with laboratory work in such a way that neither 

 shall detract from the value of the otlier. Under the head of ' 'Addi- 

 tional Facts" are stated life relations and habits of the animals 

 studied which cannot be determined from an examination of their 

 structure. Completeness or fullness in this respect is neither at- 

 tempted nor desired, but enough is given to stimulate observation. 

 The natural history text is limited to the animal forms studied 

 in the laboratory, or to closely related animals, for it is very doubt- 

 ful whether the reading about animals foreign to one's locality or 

 experience is at all conducive to observation. 



The principal emphasis is laid upon the branch of Arthropods, 

 and the subject of insects is treated first. This is done deliber- 

 ately and after much thought and trial of other ways. The first 



