THE STRUCTURE OF PLAXTS. 



Tms chapter has been prepared for the purpose of giving those who use 

 this work, some general notions upon the structure of plants. From 

 the limited space allowed, the principal facts can only be stated, and 

 those very briefly. Those who desire to be more fully informed upon 

 this subject, are referred to the admirable works of Prof. Gray. His 

 progressive series, " How Plants Grow," Lessons in Botany," and 

 " Botanical Text-Book," — the first for children, the second a compre- 

 hensive popular work, and the last an extended treatise, — are all that 

 can be desired in the way of popular and at the same time thoroughly 

 scientific elementary works. 



1. The material world is divided into Unorganized (or Inorganic) 

 substances, and Organized [or Organic) beings. The mineral substances 

 of the earth and air and water belong to the first, and plants and 

 animals to the second of these divisions. Unorganized substances have 

 neither life nor growth, and are without parts or organs adapted to 

 special offices. Organized beings have life and growth ; they start from 

 a simple germ, and go through jjrogressive stages of developement : they 

 are furnished with parts or organs which have particular functions to 

 perform, either in promoting the growth of the individual or in per- 

 petuating its kind. 



2. Organized beings are of two kinds, Vegetables and Animals. A 

 vegetable or plant may be defined as a l^eing which converts the unor- 

 ganized matter (contained in the air, water and the earth) into organized 

 material which is either directly or indirectly the food of animals. 

 Animals have not the power of appropriating unorganized substances, 

 but live upon the food furnished by plants, for the reception of which, 

 they are provided with an internal cavity or stomach. Plants are pro- 

 ducers of food, while animals are consumers of food. 



3. The study of plants in all that relates to their growth and repro- 

 duction, their resemblance to and difference from one another in the 

 structure and arrangement of their parts, their distribution over the 

 earth's surface, and whatever relates to the history of a plant, constitutes 

 the science of Botany. The science is divided into several departments ; 

 that which treats of the nature and functions of the diflerent parts or 

 organs is Structural Botany — that branch of the science of which we 

 wish.to give a brief outline in the following page?. 



4. All plants fall into two great series : 1st, those which have manifest 

 Oowers and are reproduced by seeds, — Flowering or PlicEnogamons 

 plants ; 2d, those which have no flowers and no proper seeds, but are 



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