. 



VARIATION IN COMPOSITION OF PLANTS 87 



hard and brittle, due to the increased formation of 

 fibre, and passage of nutrients into seed ; consequently 

 they are less digestible. 



Weather Conditions during Harvesting and 

 Storage. If much rain falls while the grass is being 

 made into hay, the grass may begin to ferment and 

 turn yellow in the swath. This fermentation would 

 cause some splitting up or decomposition of the 

 nutrients, with evolution of carbon dioxide gas, hence 

 food material would be lost. At the same time 

 the rain-water would dissolve a certain amount of the 

 soluble constituents out, especially the soluble carbo- 

 hydrates and to a smaller extent the nitrogenous 

 matter and fat, as will be seen in the following table. 



Effect of Rain on Red Clover Hay (Baesler's Analysis}. 



In the "heating of hay" the hay turns a bright 

 yellow or brownish colour, and, if continued much 

 further, ultimately black. Simultaneously a consider- 

 able amount of heat is generated. 



When hay is stacked too soon, the heat generated may be so 

 intense as to cause it to ignite (fire). Firing, however, does not 

 take place until a few weeks have expired, as the heat has to 

 drive off the surplus moisture before ignition will take place. 



The drier the hay is made before stacking, the less 

 will it heat. The more imperfect the drying process 

 the more it will heat ; hence, the presence of a certain 

 amount of moisture encourages these fermentative 



