THE 



BOTANICAL TEXT-BOOK 



INTRODUCTION. 



GENERAL SURVEY OF THE SCIENCE. 



1. BOTANY is the Natural History of the Vegetable Kingdom. 

 The vegetable kingdom consists of those beings (called plants) 

 which derive their sustenance from the mineral kingdom, that is 

 from the earth and air, and create the food upon which animals 

 live. The proof of this proposition will be hereafter afforded, in 

 the chapter upon the food and nutrition of plants. The vegetable 

 kingdom, therefore, occupies a position between the mineral and 

 the animal kingdoms. Comprehensively considered, Botany ac- 

 cordingly embraces every scientific inquiry that can be made 

 respecting plants, their nature, their kinds, the laws which gov- 

 ern them, and the part they play in the general economy of the 

 world, their relations both to the lifeless mineral kingdom below 

 them, from which they draw their sustenance, and to the animal 

 kingdom above, endowed with higher vitality, to which in turn 

 they render what they have thus derived. 



2. There are three aspects under which the vegetable world 

 may be contemplated, and from which the various departments of 

 the science naturally arise. Plants may be considered either as 

 individual beings ; or in their relations to each other, as collec- 

 tively constituting a systematic unity, that is, a vegetable kingdom; 

 or in their relations to other parts of the creation, to the earth, 

 to animals, to man. 



3. Under the first aspect, namely, when our attention is direct- 

 ed to the plant as an individual, we study its nature and structure, 



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