292 GEOLOGY. 



continued on through the Champlain and Terrace peri- 

 ods, the water making piece rub against piece, great and 

 small, thus furnishing the small particles that were to be 

 the nutritious part of the soil which it was to spread 

 over the country. Hugh Miller, in speaking of the soil 

 which was thus furnished to Scotland, holds the follow- 

 ing language: "It is but a tedious process through which 

 the minute lichen, or dwarfish moss, settling on a surface 

 of naked stone, forms, in the course of ages, a soil for 

 plants of greater bulk and a higher order ; and had Scot- 

 land been left to the exclusive operation of this slow 

 agent, it would be still a rocky desert, with perhaps liere 

 and there a strip of alluvial meadow by the side of a 

 stream, and here and there an insulated patch of mossy 

 soil among the hollows of the crags ; but, though it might 

 possess its few gardens for the spade, it would have no 

 fields for the plow. We owe our arable land to that ge- 

 ologic agent which, grinding down, as in a mill, the up- 

 per layers of the surface rocks of the kingdom, and then 

 spreading over the eroded strata their own debris, form- 

 ed the general basis in which the first vegetation took 

 root, and in the course of years composed the vegetable 

 mould. A foundering land under a severe sky, beaten 

 by tempests and lashed by tides, with glaciers half chok- 

 ing up its cheerless valleys, and with countless icebergs 

 brushing its coasts and grating over its shallows, would 

 have seemed a melancholy and hopeless object to human 

 eye had there been human eyes to look upon it at the 

 time ; and yet such seem to have been the circumstances 

 in which our country was placed by Him who, to " per- 

 form his wonders," 



"Plants his footsteps in the sea, 

 And rides upon the storm," 



in order that, at the appointed period, it might, accord- 

 ing to the poet, be a land 



"Made blithe by plow and harrow." 

 404. Post-tertiary Animals. There are three points 



