14 INTRODUCTION. 



41. Physiological botany is that departi^ent which relates to the 

 vital action of the several organs and tissues, including both the vital 

 and chemical phenomena in the germination, growth, and reproduction 

 of plants. It has, therefore, a direct and practical bearing upon the 

 labors of husbandry in the propagation and culture of plants, both in 

 the garden and in the field. 



42. Systematic botany arises from the consideration of plants in 

 relation to each other. It aims to arrange and classify plants into groups 

 and families, according to their mutual affinities and relative rank, so as 

 to constitute of them all one unbroken^ series or system. 



43. Descriptive botany, or phytoiogy, is the art of expressing 

 the distinctive characters of species and groups of plants with accuracy 

 and precision, in order to their complete recognition. A flora is a 

 descriptive work of this kind, embracing the plants of soma particular 

 country or district. 



44. Botanical Nomenclatuee, which is the art of properly apply- 

 ing names to the species and groups, is intimately associated with the 

 above department. Terminology relates to the explanation and appli- 

 cation of botanical terms whereby the organs of plants, with their nu- 

 merous modifications, are accurately designated. This is, therefore, 

 inseparable from Structural Botany. 



45. Ultimate aim op botany. Finally, in its extended sense, Botany com- 

 prehends also the knowledge of the relations of plants to the other departments of 

 natui'e, particularly to mankind. The ultimate aim of its researches is the develop- 

 ment of the boundless resources of the vegetable kingdom for our sustenance and 

 protection as well as education ; for the heahng of our diseases and the alleviation 

 of our wants and woes. This branch of botanical science Is called 



46. Applied eotant. It includes also several departments, as Medical Botany, 

 CT Pharmacy, Agricultural, Botany, or Ohemisiry, Pomology, &o. 



47. Plan op the work. I« the following pages, designed as a 

 complete although compendious treatise for the special convenience of 

 the learner, we shall commence with Structural Botany, whose subjects 

 (the constituent organs of plants) are conspicuous and most readily com- 

 prehended. 



48. Secondly, the cell and the elementary tissues will claim our at- 

 tention. Thirdly, we shall inquire into the vital activities of all these 

 organs, and endeavor to explain the phenomena of vegetable life. 

 Fourthly, the principles of vegetable nutrition which constitute the 

 foundation of agricultural science. 



49. In the pipth place we shall treat of Systematic Botany, the 

 principles of arrangement adopted in the Natural System, and the 

 methods of Botanical Analysis. 



50. Lastly, the Natural Orders will be defined, and illustrated by 

 our flora, both native and cultivated. 



