34 NEW AMERICAN ORCIIARDIST. 



duces inferior, but affords excellent fruits, intermixed with 

 those of a middling quality." 



Intelligent writers those on whom we may rely have 

 assured us, that the new and numerous class of fruits 

 which have arisen during the last forty years, is far more 

 precious and inestimable in point of quality, than all pre- 

 viously known. They refer in this more particularly to 

 pears. Trees of those already most renowned are here. 



Highly satisfactory specimens of many of the new spe- 

 cies which are described in the following pages, have been 

 seen and exhibited among us ; enough to convince us of 

 the decided excellence of at least a portion of those already 

 proved ; but many of the new, foreign, and renowned va- 

 rieties, of very recent introduction, are yet for trial. 



The unwearied labors of Knight, of Van Mons, of Co- 

 loma, of Hardenpont, of Duquesne, of Nelis, of Liart, of 

 Dorlain, and others, have probably effected more during 

 the last forty years, than all that had been previously ac- 

 complished during twenty centuries. 



All these fruits are recommended as highly deserving of 

 trial in our climate. From them we must make our other 

 selections, at another day, of such kinds only as prove, on 

 trial, alike adapted to our climate, the very best in quality, 

 and the most productive. 



SECTION V. OF THE GROWTH OF TREES AND PLANTS. 



Modern physiologists have demonstrated, that trees and 

 plants derive their nourishment through the extreme ends, 

 and blunt, spongy points, of the minute fibres of the roots. 

 These innumerable mouths, or spongelets, absorb and 

 drink in, without discrimination, all the fluid substances 

 which come in their way. These fluids ascend through 

 the alburnum, or sapwood, to the leaves, which are the true 

 laboratories of all plants, as well as the organs of respiration. 

 The circulation of the sap, which commences its move- 

 ment first in the branches, and last of all in the roots, is 

 produced by the attraction of the leaf-buds and leaves, 

 which are developed by the warmth of spring their 

 transpiration requiring supplies so great and continual, 

 that some plants are stated to perspire even twice their 

 weight in twenty-four hours. The true sap, thus generated 



