10 THE SOIL OF THE FARM. 



the abrading agencies of an ancient glacial period have 

 done a great deal towards commingling the detritus of 

 the different geological formations, producing wide- 

 spread *^ drift" soils of various composition. This de- 

 tritus is far from being uniformly spread over the island. 

 In some districts it is absent, while in others it forms a 

 thick mantle obscuring all the hard rocks. No richer 

 source of soil could possibly be mentioned, for our drift- 

 beds have been all formed by the breaking up of rocks of 

 different geological formations, and of various chemical 

 constituents. 



It is no doubt true that in regions where there is a 

 thick cover of '* drift " the soil has little or no relation to 

 the solid rocks below the drift, but this " drift" is there 

 really the surface ^^^rock/' in the agricultural sense of 

 that word ; so that there is no exception here to the rule 

 that, soil is rotted subsoil and subsoil is rotting rock. 



Vegetable Mould is continually forming wherever 

 plants grow. It is the foundation, and often the entire 

 source, of the organic portion of the soil. Where vege- 

 tation is scanty, or where the produce of the soil is re- 

 moved by man or animals, it occurs sparingly. Deep 

 beds of this mould are, however, met with in forests 

 under trees, and on dry land generally, wherever vege- 

 tation is rank and neglected. 



Peat, like vegetable mould, is produced by the slow 

 decay of plants and their remains in the midst of water. 

 The peat may arise simply from the accumulation of 

 neglected vegetable matter in moist situations. Where 

 successive generations of plants have groAvn and decayed 

 upon a soil, the vegetable matter increases m such a pro- 

 portion that tlie soil approaches to a peat in its nature ; 

 and if in a situation wliere it can receive water from a 

 higher district, it soon becomes spongy, and unlitted for 

 the growth of any but coarse aquatic plants. 



