CHAPTER I. 



THE PLANT AND ITS SURROUNDINGS. 



The plant the central object of study soil, climate, atmos- 

 phere, etc., are factors of its environment. Agricultural 

 chemistry. The plant a machine. Physiology. 



If I were asked to sum up the most important 

 result of the numerous advances made during the 

 past decade in agriculture and forestry, I should 

 reply the clearer and wider recognition of the 

 fact that the plant itself is the centre of the 

 subject, and not the soil, climate, season, or 

 other factors of its environment. Until com- 

 paratively recent times it was the habit of 

 farmers, foresters, planters, and gardeners, all the 

 world over, to look upon the plant as a mere 

 item or as a mysterious if important one in their 

 calculations, and to regard the soil as the chief 

 factor in their studies. 



Now all is changing, and the world is gradually 

 awakening more and more to the recognition of 

 the truth that the soil and the clouds and the 



A 



