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CONTENTS 



1 INTRODUCTION 



2 STRUCTURE AND ACTIVITIES OF CELLS 



10 



THE CELL THEOR\' 1 1 



DISTINGUISHING CAPACITIES OF LIVING ORGANISMS 12 



METHODS OF STUDYING CELLS 13 



A COMPOSITE CELL 17 



THE CHEMICAL NATURE OF PROTOPLASM 22 



FOOD 29 



CELLULAR METABOLISM 35 



CELL DIVISION 38 



Amitosis 39 



Mitosis 39 



SUMMARY 44 



3 METABOLISM IN VERTEBRATES 



ORGAN SYSTEMS RELATED TO METABOLISM 47 



The Digestive System 47 



The Circulatory System 50 



The Respiratory System 54 



The Excretory System 56 

 THE KINDS OF TISSUES: HISTOLOGY 58 



Epithelial Tissue 59 



Sustentative Tissue 61 



Vascular Tissue 63 



Contractile Tissue 67 



Nervous Tissue 68 



Organs 69 

 DIGESTION 70 

 ABSORPTION 74 



TRANSPORT AND STORAGE OF FOOD 76 

 RESPIRATION 79 

 EXCRETION 82 

 SUMMARY 84 



46 



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