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lation throughout the winter ; their juices are less wa- 

 tery than those of other plants, and probably less liable 

 to be congealed by cold, and they are defended 

 by stronger coatings from the action of the 

 elements. 



The production of the other parts of the plant 

 takes place at the time the leaves are most vigorously 

 performing their functions. If the leaves are stripped 

 off from a tree in spring, it uniformly dies, and when 

 many of the leaves of forest trees are injured by 

 blasts, the trees always become stag-headed and un- 

 healthy. 



The leaves are necessary for the existence of the 

 individual tree, the flowers for the continuance of the 

 species. Of all the parts of plants they are the most 

 refined, the most beautiful in their structure, and ap- 

 pear as the master-work of nature in the vegetable 

 kingdom. The elegance of their tints, the variety of 

 their forms, the delicacy of their organization, and 

 the adaptation of their parts, are all calculated to 

 awaken our curiosity, and excite our admiration. 



In the flower there are to be observed, 1st, the 

 calyx, or green membranous part forming the support 

 for the coloured floral leaves. This is vascular, and 

 agrees with the common leaf in its texture and organi- 

 zation ; it defends, supports, and nourishes the more 

 perfect parts. 2d. The corolla, which consists either 

 of a single piece, when it is called monopetalous, or of 

 many pieces, when it is called polypetalous. It is 

 usually very vivid in its colours, is filled with an al- 

 most infinite variety of small tubes of the porous kind 5 



