G THE CHAIN OF LIFE. 



jjioduced by accumulation of corals and shells. Such deposits 

 must not only have been successive, but must have required 

 a long time for their formation. 



In Fig. 4 we have a bed of coal and its accompaniments. 

 The coal itself was produced by the slow accumulation of 

 vegetable matter on a water-soaked soil, and this was buried 



!!! 



: 4 



Fio. 4. — Inclined beds, holding fjssil plants. Carboniferous. S juth Joggins, Nova Scotia» 



1. Shale and sandstone. Plants with Spirorbis attached ; rain-marks (?). 



2. Sandstone and shale, 8 feet. Erect Calamites. \ An erect c jniferous (?) tree, rooted 



3. Gray sandstone, 7 feet. \ on the shale, passes up through 15 



4. Gray shale, 4 feet. J feet of the sandstones and shale. 



5. Gray sandstone, 4 feet. 



6. Gray shale, 6 inches. Prostrate and erect trees, with rootlets, leaves, Naiadiies, and 



Spirorbis on the plants. 



7. Main coal-seam, 5 feet cjal in two seams. 



8. Underclay, with rootlets. 



under successive beds of sand and clay, now hardened into 

 sandstone and shale, some of the beds holding trees and reed- 

 like plants, which still stand on the soils on which they grew, 

 and which must have been buried in sediment deposited in 

 inundations or after subsidence of the land. In this section 

 we may also observe that the beds are somewhat inclined; 



