PREFACE 



IT seems to the author that three kinds of work should 

 be included in the elementary study of zoology. These 

 three kinds are: (a) observations in the field covering 

 the habits and behavior of animals and their relations 

 to their physical surroundings, to plants, and to each 

 other ; () work in the laboratory, consisting of the study 

 of animal structure by dissection and the observation of 

 live specimens in cages and aquaria ; and (c) work in the 

 recitation- or lecture-room, where the significance and 

 general application of the observed facts are considered 

 and some of the elementary facts relating to the classifi- 

 cation and distribution of animals are learned. 



These three kinds of work are represented in the course 

 of study outlined in this book. The sequence and extent 

 of the study in laboratory and recitation-room are defi- 

 nitely set forth, but the references to field-work consist 

 chiefly of suggestions to teacher and student regarding 

 the character of the work and the opportunities for it. 

 Not because the author would give to the field-work the 

 least important place, he would not, but because of the 

 utter impracticability of attempting to direct the field- 

 work of students scattered widely over the United States. 

 The differences in season and natural conditions in vari- 

 ous parts of the country with the corresponding differences 

 in the * ' seasons ' ' and course of the life-history of the 



221739 ' 



