AGRICULTURAL CLOVERS 69 



to gravel, or gravelly clay. In poor land it does better, and is 

 less sensitive to atmospheric influences, than Red Clover, and is 

 of great importance on land which cannot be depended on to 

 gi'ow Perennial Red Clover. In early spring it produces very 

 little food, and the plant is so dwarf that it is practically 

 useless for cutting. For a crop of hay Alsike is preferable. 

 StiU, Perennial White Clover forms an essential constituent 

 of every good pasture. All cattle eat the herbage with 

 reUsh, but it is less useful for the production of milk than of 

 flesh, and is of special service in fattening sheep. No doubt the 

 crop is more palatable to stock before the plant flowers than 

 afterwards ; indeed, a profusion of flowers is no indication of 

 an abundant bite. White Clover is not suitable for culture 

 alone, and it is better for cattle when mingled with grasses, 

 especially with Perennial Rye Grass. The Norfolk farmers 

 largely use it for ewes and lambs, but from difference of 

 climate the favourable opinion they entertain is not shared by 

 practical men in the West of England. 



The fertilisation of White Clover is aided by insects. 

 From ten flower-heads visited by bees Darwin obtained ten 

 times as many seeds as from a corresponding number protected 

 by gauze. On a subsequent occasion he faUed to obtain a 

 single fertile seed from twenty protected heads. 



AVhen White Clover is one of the constituents of mixed 

 grasses and clovers, the application of ammonia salts and 

 nitrate of soda so develops the gramineous herbage that there 

 is a smaller growth of White Clover than when the land is 

 left unmanured. JMineral manures— basic slag especially — con- 

 siderably augment the crop of White Clover, and a similar 

 result is obtained from dressings of marl or vegetable ash. 



For illustration, description, and chemical analysis, see 

 pages 180 and 181. 



