8 INTRODUCTION 



thought, and though some of them may appear indefinite, 

 the student is thus led to organize all the knowledge he has 

 and all that he can legitimately obtain toward the answer. 

 A normal child is not content with knowing the structure 

 of an animal nor the comparative structure of several ani- 

 mals ; he wants to know how the animals in question use 

 that structure in living. He wants to know how they select 

 and obtain their food, how they treat their fellows, especially 

 those of their own species, and how they successfully over- 

 come the vicissitudes of climate and the onslaughts of their 

 enemies. He delights to look upon the animal world as a 

 struggle for existence — a struggle which requires all the 

 strength, instinct and intelligence which the animal can 

 command. In other words tlie child prefers to approach 

 Zoology through animal ecology, and this book therefore 

 emphasizes the ecological factors in every study. Animal 

 ecology cannot be taught from books, however valuable 

 they may be if rightly used, neither can it be successfully 

 studied from dead forms in the laboratory ; but it requires 

 the study of living, active forms not in the laboratory only 

 but in their natural environment. Field trips in which the 

 teacher organizes the work and directs the observation and 

 collecting, will be found of inestimable value and should 

 be taken as often as circumstances will permit. 



Dissection of type forms is required in all cases, and 

 should be thoroughly done; but it is regarded as a means 

 of finding how the animal solves certain life problems rather 

 than as an end in itself. The student looks beyond the dissec- 

 tion to the animal's adaptation to its environment, and the 

 dread of dissection with which every teacher has to con- 

 tend, rapidly disappears. 



