PART I. 



r " ..-;; INSECTS. I ' y "... ^ 



CHAPTER I. 

 INTRODUCTION TO INSECTS. 



Biology. 



Biology, the word, is made from the two Greek nouns 

 bios, meaning life, and logos, meaning speech, reason, word, 

 that is, something given with authority. Hence biology 

 discusses life in its many phases, its structural means of 

 maintaining itself, and its power of perpetuating itself 

 from one generation to another. Biology, then, concerns 

 itself with both plants and animals, and we have plant 

 biology and animal biology. 



Zoology. 



Zoology is built from the two Greek nouns zoon, 

 meaning an animal, and logos; hence zoology is the discus- 

 sion of animal life in its many phases of activity and power. 

 The systematic zoologist divides the many forms of animal 

 life into branches according to their large similarities and 

 dissimilarities. He may, for example, establish the two 

 classes, Protozoa one-celled, non-differentiated animals, 

 very simple in structure; and Metazoa many-celled 



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