THE VALUE OF GREEN FORAGE CROPS. 53 



welcome rain, in moderate quantity, as much as in hay-making he 

 would dread it. The secret of the process lies in the thorough ex- 

 clusion of air from the vegetable mass in the pit, or silo. The tissues 

 of which all plants are composed are made up of minute closed cells, 

 or elongated tubes of very small calibre : these are hollow within, 

 and the cavities must be filled either with air or water. When the 

 plant is fresh and green, it is surcharged with moisture which pene- 

 trates its tissues, and fills these cavities : when wilted, the water 

 escapes by evaporation, and air takes its place. This air is retained 

 with great tenacity, and its expulsion is a matter of much difficulty. 

 Hence the importance of packing away the corn, or other green 

 matter, in as fresh and succulent a condition as possible, and the 

 advisability of sprinkling it w r ith water if wilted, in order to keep it 

 moist, and so prevent the entrance of air. 



Again, in a dry spring the hay crop may fail ; but corn can be sown 

 at any time, in this latitude, between the middle of May and 10th of 

 July, and, if need be, in continued succession. Very rarely is the 

 whole season unpropitious : if the spring is too dry, the late summer 

 is more favorable : hence, with such a crop as corn, the chances are 

 greatly multiplied. 



