204 BOARD OF AGRICULTURE. 



Afternoon Session. 



The Convention met at the hour appointed, Mr. Flint in 

 the Chair. 



OBSERVATIONS UPON THE PHENOMENA OF PLANT-LIFE. 



BY PRESIDENT W. S. CLARK. 



The observations concerning "The Circulation of Sap in 

 Plants," which I had the honor of presenting before the 

 Board of Agriculture at their last country meeting, were so 

 kindly received at the time, and awakened so much interest 

 after their publication, that I have found it impossible to 

 refrain from further investigations upon the phenomena of 

 plant-life. Among the subjects to which special attention 

 has been directed during the year, the following may be 

 enumerated, viz. : 



First. The structure, composition and arrangement of the 

 winter-buds of hardy trees and shrubs. Specimens for study 

 were collected, in January and February last, from one hun- 

 dred and forty species, and some facts of interest recorded. 



Second. The percentage of water to be found in the 

 branches and roots of trees during their annual period of 

 repose, as well as when in active growth. 



Third. The phenomena and causes of the flow of sap from 

 wounds in trees when denuded of their foliage, as well as the 

 flow from the stumps of woody and herbaceous plants when 

 cut near the ground in summer. In connection with this 

 subject, an attempt has been made to determine what species 

 flow, how rapidly and copiously, and under what circum- 

 stances. 



The pressure exerted by the sap exuded from detached 

 roots of trees under ground, as well as that exhibited upon 

 gauges placed at different elevations from the earth, has also 

 been very carefully observed upon a number of species. 



The facts determined are even more remarkable than were 

 noticed last year, and are particularly important in the case 

 of the sugar-maple. 



