449 



Fig. 303. Showing a stump standing as it grew in Coal Measures, near ( 

 Scotland. 



ied where they fell, without being drifted by moving waters from 

 e, place to another. (4). In many cases, the layer of rock next 

 overlying a coal-bed contains abundant remains of vegetation, 

 especially in its lower part, as if the conditions which brought about 

 its deposition resulted in the destruction of the forest growth which 

 had preceded. In such situations, trunks of trees 50 and 60 feet 

 long, and 2 or 3 feet in diameter, have been found. 



While it is confidently believed that most of the workable coal 

 represents the growth of vegetation in situ, it is not to be understood 

 at coal was never formed from vegetation which drifted together. 

 In the formation of a coal-bed, three things are to be accounted 

 or: (i) The conditions under which the necessary quantities of 

 vegetable matter accumulated; (2) how it was kept from decay; and 

 ) how changed into coal. 



Accumulation of organic matter. Large marshes, or marshes 

 in low surroundings, are the only places where vegetable matter is 

 now accumulating in quantity, with little admixture of sediment. 

 Thus in the marshes along some parts of the Atlantic coast (Fig. 

 394), there are quantities of organic matter which, locally, is mixed. 



|'":h little sediment. In Dismal Swamp, the stems, branches, 

 ves, and fruits of the trees, shrubs, and herbs which grow there, 



