DESCRIPTION OF FEEDING-STUFFS 157 



potash-phosphate manure, without nitrogen, tends 

 very largely to induce the valuable leguminous 

 plants. The causes of this are to be found in the 

 special requirement of the two classes of plants ; 

 grasses need nitrogen, whilst the Leguminosae can 

 get their supply of this element from the atmosphere 

 provided they have sufficient potash and phos- 

 phates. 



If more mineral substances are at the disposal of 

 the plant than it requires for growth, it nevertheless 

 takes up some of the excess, a circumstance which 

 is of great importance as regards the supply of lime 

 and phosphoric acid to domestic animals. 



(e) The weather conditions during growth in- 

 fluence not only the quantity, but also the com- 

 position of the fodder plants. In wet years the 

 plants usually contain more water and grow to 

 a greater height. The stem, which is rich in crude 

 fibre, thereby increases at the expense of the more 

 valuable leaves, and a coarse food less palatable and 

 nutritious is the result. A period of drought, on 

 the other hand, causes the plants to be shorter 

 and more compact, with small leaves and stems, 

 which quickly lignify. If the drought is long- 

 continued the entrance of mineral substances into 

 the roots is prevented, and so the fodder is poor in 

 lime and phosphoric acid, and may give rise to 

 diseases of the bones. 



(/) The fodder plants have a different effect in 



