THE CONTENTS OK THK SOIL 23 



soil. Some laiuls liavo very i»on)Us <)r"rotteu" 

 stones, and tlirse j)ass (|uickly into soil. Stonos 

 are no donlit a usft'nl reserv«' force in Tarni 

 lands, giving n}) their fertility very ^nadually, 

 and thereby saving some of the wast«'fulness of 

 eareless husl)andry. The general tendency, in 

 nature, is for soils to become finer, nK^re homo- 

 geneous, an<l better for tlic gi'owth of j)lants. 



.'»7. 1)111 tlu're are greater movements than 

 these. Soil is often transjtorted long distances, 

 chietly by means of three agents: moving water, 

 ice and <n<>\v, wind. Transported soils are apt 

 to be veiy uidike the underlying rock (or origi- 

 nal surface), and tlun' are often very hetero- 

 geneous or <'onglomerate in chni-acter. Soils 

 which remain where th«'y are formed (1^7) 

 naturally partake of the nature of the bed- 

 rock, an<l arc generally more homogeneous than 

 transported soils, as, for exanijile, the liniestoiie 

 soils which overlie great deposits of linie-in»k. 



'.\f^. Moving water always moves land. The 

 beating of waves wears away rocks ;nnl stones 

 and breaks up debris, and deposits the mass on 

 or near tlic shore. Streams eai'rv soils long 

 distances. The parti<'les may be in a state of 

 suspension in the water, and be precijiitated in 

 tlie quiet«'r parts of the streaju or in bayous or 

 lagoons, or they may be driven along the bed 

 of the stream l)y the force of the current, and 



