X PREFACE. 



3. The Order of the Youth's Mental Activity and Interest. 

 The writer believes that the youth at early high- school 

 age normally gets, and needs to get, a general or syn- 

 thetic view (howbeit superficial) at the beginning; that 

 this is normally followed by analysis or study of parts; 

 and later again a fuller synthesis of these special studies 

 may be had and is demanded by the mind as a normal 

 completion of its work. This will account for the early 

 presentation of a synthetic view of the animal kingdom 

 (Chapter III) and the general synoptic chapters that in- 

 troduce the subject broadly, followed by the detailed study 

 of the phyla of animals, and last of all by some chapters 

 giving a renewal and fuller statement of the general or 

 evolutionary view. 



The individual chapters are constructed on the same 

 pedagogical assumption. 



Certain special devices mark the book in 

 SPECIAL its effort to aid the teacher to keep the 

 DEVICES. problem-raising and solving attitude in 

 the pupil : 



1 . The brief and superficial keys for the tracing of ani- 

 mals roughly to their phyla or classes or families will be 

 found to meet a need on the part of the pupil. His first 

 question usually is, " What is this animal ? " Some most 

 valuable habits of mind are exercised by the use of such 

 keys in the partial self-answering of this question. 



2. The suggestions of calendar studies and spring field- 

 work are particularly calculated to bring the pupil into 

 a sympathetic understanding of nature. They further 

 give to the student's interest an extension in time, which 

 it is very important that he should cultivate. 



3. The suggestive questions in connection with the 

 various figures are designed to increase the student's 



