INTBODUOTION. 13 



Very many vegetable substances or products are ternary 

 compounds, or composed mainly of oxygen, carbon, and 

 hydrogen; while very many of the animal substances or 

 products are quaternary compounds, or composed of 

 oxygen, carbon, hydrogen, and nitrogen. 



Most plants, but by no means all of them (especially 

 the lower forms), are stationary, or have no power of 

 locomotion ; while animals, also with numerous exceptions, 

 locomote freely from place to place. 



Sensation is possessed by plants in a very much less 

 marked degree than by animals. 



The study of plants may be solely with reference to their 

 visible parts or organs, and this part of the science is called 

 Organogeaphy, or Structural Botany. When the investi- 

 gation touches the minute or microscopic structure of 

 plants or their parts and products, it is called Minute 

 Anatomy, or Histology. The study of the parts of the 

 plant with reference to their functions or office, or their 

 so-called vital actions, comes under the head of Vege- 

 table Physiology. The classification of plants and what 

 directly appertains to it constitutes Systematic Botany. 

 All the plants of any region are called the Flora of that 

 region. Fossil Botany treats of fossil plants, or those 

 which existed in previous geologic times, and whose remains 

 or impressions are found in rock-strata. The application 

 of botanical knowledge in the arts, industries or pursuits 

 of life is designated by the term Applied Botany. This 

 may be Agricultural, Horticultural, or Medical Botany, 

 etc. Economic Botany is commonly used to indicate a 

 study in general of the vegetable products and their uses. 



