vi Preface. 



As the facts concerning the different kinds of animals become known, 

 they must be sorted and arranged according to some system. The 

 basis of classifying animals is structure. Of course the beginner 

 cannot go deep into anatomy, but he must know some of the more 

 important facts of structure or else his attempt at classification is com- 

 paratively useless. Since it is usually impracticable to study animals 

 in systematic order, the student must learn to arrange his knowledge 

 as he proceeds. This is not different from mental growth in other 

 lines. Our experiences do not come to us classified. Just as an 

 orderly merchant sorts his new goods, and arranges them on shelves 

 with previously acquired articles of the same kinds, so the student must 

 arrange in systematic order his ever increasing stock of knowledge. 



At the close of the volume will be found the classification of the 

 animal kingdom according to Parker and Haswell, whose arrangement 

 is considered the most authoritative of recent works. 



THE VALUE OF THE STUDY OF TYPES. Real knowledge comes 

 through experience. What one learns through another is information. 

 The teacher must distinguish between first-hand knowledge and second- 

 hand knowledge. Now the number of animals that any student can 

 examine is small in comparison with the number in existence. The 

 study of the animal kingdom is greatly simplified by the fact that, with 

 all the variety of animal forms, there are actually but few different plans 

 of structure. One important part of the teacher's work is to select the 

 best types for careful study. On the. foundation thus laid much infor- 

 mation may be built. If one had never seen a Crustacean, he would 

 get little from reading about Crustaceans. But, after studying a cray- 

 fish, a fairly clear idea of a lobster or a crab may be obtained by read- 

 ing, for a foundation has been laid in sense perception. 



The knowledge of a type may ba compared to a peg in a wall ; if it 

 is driven in solid, it will hold many facts of information. 



The types selected, their number, and the thoroughness with which 

 they are studied will naturally vary with the locality, season, the age 

 of the student, the time allotted to the study, and various other 

 circumstances. 



DEFINITIONS. The student should be taught to make definitions. 

 By comparing a number of related forms, as suggested in the practical 

 work on insects, the student should see what characteristics they have 



