38 ON ASPECT. 



of its most important functions in such a manner, if a 

 strong wind should blow at any time for the space 

 only of a few hours, the flow of sap is seriously 

 checked, evaporation proceeds at a most exhausting 

 rate, and the leaves and young shoots being speedily 

 emptied of the moisture accumulated in their cells 

 and vessels, become rigid, and their pores completely 

 closed. The vegetative powers of the plant being 

 thus prostrated, cannot resume their functions till 

 after the wind has ceased for several hours, or even 

 days, according to its previous violence and duration. 



I have made repeated observations on the growth 

 of the leading shoots of vines in the height of the 

 growing season, and have many times noted the fact, 

 that during the space of twenty-four hours, when the 

 wind has blown briskly, the shoots exposed to its 

 influence have not perceptibly grown at all ; while, 

 shortly afterwards, the wind having entirely sunk 

 away, the same shoots have grown upwards of three 

 inches in a similar space of time, the temperature of 

 the air in a sheltered situation being alike during each 

 period. 



And if two young vines be planted by the side of 

 each other, against a wall exposed to the north, for 

 the purpose of trying the expernnent, by excluding 

 the influence of the sun's rays, and one be kept 

 nailed to the wall every five or six inches of its 

 growth throughout the summer, and the other be 

 suflered to be blown about without any such protec- 

 tion; the former will be found at the end of the 

 season, to have grown in the size and extent of its 

 shoots, three or four times as much as the latter. 

 Nothing, indeed, can be more tender, or less calcu- 

 lated to withstand the effects of the wind than the 

 extremities of the young shoots of a vine, which, 

 from being extremely porous, are almost as suscepti- 

 ble of its withering influence as the Sensitive Plant is 

 of the touch of the hand. 



Many instances might be circumstantially detailed 

 of the injurious effects of the wind upon established 



