THE SELECTION OF GKASSES AND CLOVERS. 75 



to be independent of the presence of potasli in the soil, and 

 will consequently flourish where clovers can scarcely maintain 

 existence, or fail entirely. 



Yarrow is a plant for pastures, not for meadows, and its 

 seed should be excluded from the mixture for a crop that is 

 to be generally mown. Sheep are very fond of it, and it is 

 believed to give an excellent flavour to mutton, venison, and to 

 butter also, notwithstanding its astringent qualities. 



Yarrow will grow on dry gravels and light sands that will 

 hardly support any other plant, and no summer is too hot for 

 it. So great is its power of enduring drought that after a dry 

 season there is always a large demand for the seed, and as it 

 is difficult to obtain of good growth, the price runs up to an 

 extravagant figui^e. 



Ammonia salts appear to be inimical to the growth of 

 Yarrow, nitrate less so, but heavy doses of any ammoniacal 

 manure are certain to reduce its bulk by increasing the strength 

 of surrounding grasses. Mineral manures alone seem to favour 

 its development. 



The botanical description and chemical analysis are given on 

 page 174, facing an illustration. 



Medicago sativa [Lucerne). — The name of this plant 

 is o-enerally supposed to be derived from the canton or town 

 of Lucerne, in Switzerland. But Dr. Stebler controverts this 

 opinion, although he is at a loss to account for its appellation. 

 Lucerne was known to the ancient Greeks and Eomans as a forage 

 plant. It is mentioned by Virgil, and at the beginning of the 

 Christian era by several agricultural writers. In Persia and other 

 Eiistern countries the plant is still used for horses. 



Eecent wet summers have much diminished the culture of 

 Lucerne in England, but a few dry seasons will restore it to 

 favour, although English farmers have never appreciated its 

 merits to the same extent as their continental brethren. In part, 

 no doubt, this is owing to climate, and in part to soil. Lucerne 



