SPECIAL PURPOSES OF BOTANIC GARDENS. 171 



of the reader to the great exotic nurseries near oui' metro- 

 poKtan cities and in other parts of the country, Tvhich, 

 though conducted on commercial principles, are sub- 

 stantially botanic gardens, and are among not the least 

 remarkable instances of the union of capital, enterprise, 

 skiU, and industiy that are to be found in the present 

 day. 



Special Purposes of Botanic Gardens. — In the pre- 

 ceding remarks it is imphed that botanic gardens are 

 intended to be the means of pubhc instruction : we may 

 now notice some of the particular expedients for the 

 accomplishment of this desirable end. 



All botanic gardens are or ought to be furnished with 

 systematic arrangements of herbaceous plants — a minor 

 one according to the Linneean, and a more extensive one 

 on some one of the natm'al systems. As a pendant to 

 these, there ought to be a general arboretum, in which 

 all ligneous or wooded plants, wliich, as they cannot be 

 conveniently grouped in the herbaceous ari'angements, 

 may be put into scientific combination ; and unques- 

 tionably this is best done on the principles of the 

 natm'al orders and families. Besides, there should be a 

 separate arrangement of medical plants. To give specific 

 dii'ections on these points does not fall within om^ 

 present design. We content ourselves, therefore, with 

 merely alluding to them; and we proceed to indicate 

 some other objects which, it is desirable, should be kept 

 in \iew more fully than heretofore in the formation of this 

 species of garden. 



Territorial arrangements of plants have been recom- 

 mended, and, we humbly think, have received too little 

 attention ; for, being skilfully executed, they would pos- 

 sess a high degree of interest. There are difficulties, 



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