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EDWARD C. JEFFREY 



modified wood. The nature of the others can best be understood 

 from Fig. 7. This represents a portion of the last figure, much 

 more highly magnified. The dark stripes are now seen to contain 

 numbers of very light-colored bodies or spores. 



Fig. 8 shows the organization of a very highly bituminous coal 

 from Kentucky. The crenulated bands corresponding to layers of 

 modified lignitic substance stand out very clearly in this illustra- 

 tion. Between the woody or lignitoid zones are darker stripes 

 variegated with light linear bodies. The latter are compressed 



'(M^^'^'VsB^ 





Fig. 7 



Fig. 8 



spores. Fig. 9 shows a part of the foregoing highly magnified, 

 and the canneloid nature of the darker bands alternating with 

 the lignitoid layers can now be clearly ascertained. 



Further examples of coals may now be considered. Fig. 10 

 shows the structure of a bituminous coal from European Russia. 

 Clearly it is largely composed of spores. Through the courtesy 

 of M. Zalessky of the Comite Geologique of St. Petersburg, I have 

 had the opportunity of examining a considerable number of coals 

 from European as well as Asiatic Russia, with similar results as 

 regards organization (except of course the coals of paralic origin). 

 Fig. II reveals the structure of non-coking bituminous coal from 

 Indiana. The conditions presented are the same as in the case of 

 the Illinois coal, with the exception that the spore material is very 

 scanty, as indeed is the case with all lean bituminous coals, in 



