TABLE OF CONTENTS ix 



CHAPTER VII. 



THE BIOLOGY OF AN ANIMAL: THE COMMON EARTHWORM (Continued.) 



PAGE 



General Physiology. The animal and its environment. Definitions. 

 Adaptation, structural and functional, of organism to environment, 

 Origin of adaptations. Effect of their persistence and accumulation. 

 Natural selection through the survival of the fittest. The need of an 

 income of food to supply matter and energy. Nature of the income. 

 The food and its journey through the body. Alimentation. Diges- 

 tion and absorption. Circulation. Metabolism. The outgo. Inter- 

 action of the animal and the environment. Summary 97 



CHAPTER VIII. 



THE BIOLOGY OF A PLANT: TEE COMMON BRAKE OR FERN. 



A representative plant. Ferns taken as a type. Their wide distribution. 

 The common brake. Its name, habitat, size, etc. General morphol- 

 ogy of its body. Its differentiation, autero-posterior and dorse-ventral. 

 Its bilateral symmetry. The underground stem. Origin and arrange- 

 ment of the leaves. Internal structure of the rhizome and the three 

 great tissue-systems. The elementary tissues of plants. Histology of 

 the rhizome. Roots and branches. Embryonic tissue and the apical 

 cell. How the rhizome grows. The frond or leaf of Pteris and its 

 structure. Chlorophyll-bodies. Stomata. Veins 105 



CHAPTER IX. 



THE BIOLOGY OF A PLANT: THE COMMON BRAKE (Continued). 



The various methods of reproduction in Pteris. Sporophore" and 

 oophore. Alternation of generations. Sporangia. Spores. Ger- 

 mination of the spores. Protouema. Prothallium. The sexual 

 organs. Autheridia. Male germ-cells. Archegonia. Female gerin- 

 cells. Fertilization. Segmentation. Differentiation of the tissues. 

 The making of the body 130 



CHAPTER X. 



THE BIOLOGY OF A PLANT: THE COMMON BRAKE (Continued). 



Physiology, The fern and its environment. Its adaptation. A defini- 

 tion of life. The need of an income of matter and energy. Income 

 of Pteris. Its power of making foods, especially starch. The circu- 

 lation of foods through the plant-body. Metabolism. Outgo. Res- 

 piration. Interaction of the fern and the environment. Special 



