CONTENTS 



SCIENCE AND SOCIETY. EXTERNAL AND INTERNAL 

 STRUCTURE OF THE PLANT 



PAGE 



The general public's meagre knowledge of botany. Two old- 

 fashioned types of botanists. The contemporary trend of 

 science. Morphology and physiology; form and life. Two 

 reasons for the comparative backwardness of botany : the 

 logical and the practical reason. Art and science. Agriculture 

 and the physiology of the plant. Science and the general 

 public in mutual relationship. 



Survey of the external organs of a flowering plant. Meta- 

 morphosis. Spore-bearing plants of earlier date and simpler 

 in structure than seed-plants. A spore a cell. The cell 

 the foundation and beginning of every organism. These facts 

 in relation to the problem of the origin of organisms. Treat- 

 ment of subject ....... i 



II 



THE CELL 



Law of the conservation of matter. Origin of plant-substance 

 in the external environment. Elements and compounds 

 entering into the composition of plants. Three fundamental 

 groups of chemical compounds : albuminoids, carbohydrates, 

 fats. Chemical and microscopic investigation of the plant. 



Absorption of nutrient substances by the plant. General 

 conception of the diffusion of matter. Diffusion of gases and 

 liquids. Colloids and crystalloids. Transformation of substances 

 in the cell explains their absorption. Fundamental mechanism 

 of the nutrition of the cell 35 



III 



THE SEED 



Structure of the seed and external phenomena of germination. 

 Three conditions of germination : water, air, heat. Mechanical 

 function of water. Chemical function of water. Ferments. 

 Diastase. Pepsin. Insectivorous plants. Independence of 

 the parts of the embryo. Artificial nutrition of the embryo. 

 Mechanism for the translocation of the nutrient substances in 

 the plant. 



The seed in relation to air ; evolution of carbonic acid, 



xiii 



