THE MODE OF ORIGIN OF COAL 



225 



contrast to fat coking and gas coals. Fig. 12 illustrates the organi- 

 zation of a bituminous coal from St. Caterina, South America. 

 The spores and lignitoid substances are as characteristically present 

 as in the other cases. Fig. 13 shows the structure of a high-grade 

 steam coal from Virginia. Here, as in the other cases described 

 for bituminous coals, spores as well as Hgnitoid substance are found. 

 As a final illustration, in Fig. 14 is shown a coal from Lancashire 

 in England. The narrow stripes of lignitoid and the abundant 

 light-hued spores can readily be discerned. 



Fig. 9 



Fig. 10 



Through the courtesy of the Director of the United States 

 Geological Survey and Dr. David White, Chief Geologist, I have 

 had the opportunity of examining nearly two hundred coals from 

 various states of the Union and from Alaska. The results of investi- 

 gation so far as bituminous coals are concerned, from whatever 

 geological horizon obtained, showed in all instances the presence 

 of a greater or less amount of spore material. Through the kind- 

 ness of the Director of the Geological Survey of Canada, I have 

 been able to examine into the structure of the Mesozoic coals of 

 the Canadian West and Vancouver Island, as well as the coking 

 and non-coking Carboniferous and Permian coals of New Bruns- 

 wick, Nova Scotia, and Cape Breton Island. The results here 

 were similar to those obtained in American coals. The coal deposits 

 of England and Scotland have also supplied numerous and varied 



