92 STEVENSON— FORMATION OF COAL BEDS. [April :8, 



structure is very difificult. The matt coal consists mostly of prosen- 

 chymatous cells, which von Giimbel thinks derived from parts of 

 leaves ; much epidermis material is present along with spore- 

 like bodies and broken fibrous coal. His conclusions in respect to 

 these matters are like those reached by Dawson. Von Giimbel 

 proved definitively the intimate resemblance of cannel, boghead and 

 other forms to each other and to the Lebertorf of East Prussia. He 

 recognized algas-like forms along with spores in bogheads and 

 cannels, thus anticipating much which has been published in later 

 years. His figures illustrate well the characteristic forms, but evi- 

 dently he had doubts respecting the relations, as he refrained from 

 applying names to the forms. 



Morris, Wethered and others early recognized spores in coal and 

 some were inclined to attribute to these a very important share in 

 the accumulation of coal beds. They seem to be in all coals. 

 Nathorst"* found macrospores very abundant in the great coal of the 

 Devonian on Bear Island, south from Spitzbergen. Wethered and 

 some others were regarded by Newberry and by Dawson as placing 

 too much stress on the contributions by spores ; while recognizing 

 that spores are almost always present, and at times even in large 

 numbers, they thought that these hardly deserve consideration as 

 important constituents of coal. Kidston^^ has presented the matter 

 in a simple way, which seems to meet requirements. He says that 

 the quantity of spores from the lycopods was unquestionably enor- 

 mous, and that they entered largely into the formation of some coals. 

 There are bands composed wholly of megaspores and of micro- 

 spores, varying in thickness from a mere membrane to a centimeter 

 or more. In coal broken transversely, they give a zoned appearance, 

 the bands of spores being distinguished by their dull color within 

 the brilliant coal. 



Van Tieghem,"*' in studying sections of flint concretions prepared 



^ A. G. Nathorst, " Zur der devonischen Flora der Briren Insel," Handl. 

 K. Svens. Vet. Akad., B. 36, No. 3, 1902, pp. 40-43- 



"" R. Kidston, " Les vegetaux houillers recueillis dans le Hainaut beige," 

 Mem. Mus. Roy. d'Hist. Nat. de Belgique, Tome IV., 191 1, p. 208. 



*" Ph. van Tieghem, " Sur le ferment butyrique (Bacillus amylobacter) a 

 I'epoque de la houille," C. R., Vol. 89, 1879, p. 1102. 



