264 RECENT FORMATIONS. 



armour and coins of the same invaders, at a depth of not 

 more than five feet, and this all that had accumulated since 

 the time they marched their legions across the Lowlands of 

 Scotland. As with the peat-mosses of Britain, so with 

 those of Holland and the north of Europe generally, those 

 of Canada, and North America, and indeed of all tem- 

 perate and coldly-temperate latitudes. They are of all ages, 

 of varying dimensions and thickness, and of all degrees of 

 purity, from masses wholly and exclusively vegetable, to 

 others more or less intermingled with earthy debris, or 

 with the siliceous and ferruginous accumulations of micro- 

 scopic plant-growths and animalcules. In warmer latitudes, 

 swamp-growths, jungle-growths, and other kindred vege- 

 table accumulations make their appearance, the vegetable 

 mass in these cases being more macerated and decayed than 

 in the true peat-moss, but still wholly or almost wholly of 

 organic origin. These peats and swamp-growths are in 

 reality the coal-formers of the present day (see Sketch No. 

 9); nor let it be thought that in the aggregate they are 

 either of inconsiderable thickness or of limited surface. 

 In the peat-bogs of Europe, 20, 30, and 40 feet are no un- 

 common depths ; the tundras of Northern Asia, though 

 less pure in composition, are of much greater extent and 

 thickness; the " Dismal Swamp" of the Southern States 

 of America is 40 miles long by 25 miles broad ; the peat- 

 moss of Anticosti is stated by Sir William Logan to be 80 

 miles long, with an average width of two miles; and those 

 in the lake regions of sub-arctic America are of still more 

 extensive dimensions. 



As with vegetable accumulations, so with those of animal 

 origin the coral-reefs, shell-beds, foraminiferal deposits, 

 bone-shoals, and guano islands of the current epoch. The 

 most obvious of these are perhaps the coral-reefs the slow 

 but incessant secretions of myriad polypes within all the 



