154 STEVENSON— FORMATION OF COAL BEDS. [April 18, 



characterize ordinary upland plants, so that the absorbing surface is 

 reduced, while the protected leaves prevent rapid loss by evapora- 

 tion. The rootlets contain abundantly a mycorrhizal fungus, which 

 fills many cells and forms a network outside on the cell wall. Simi- 

 lar fungi were discovered by Miss Ternetz in rootlets of the cran- 

 berry and other swamp plants. Coville finds them in most of the 

 acid-loving plants, such as the laurel, birch, chestnut, conifers, oaks, 

 club mosses, ferns, orchids, and thinks probable that they convert 

 the unavailable nitrogen of acid, peaty soils into available nitrogen, 

 so as to provide proper nutriment to the plants. 



Fungi, myriapods and insect larvje are efficient in hastening 

 decomposition. Coville says that myriapods are almost incredibly 

 abundant in the very acid laurel {Kalmia) peat. Renault^^* pre- 

 sented to the geological Congress at Paris a synopsis of his great 

 work on the " Microorganismes des combustibles fossiles," in which 

 he indicated the work performed by lower types of life. Study of 

 the Grand'Croix flints proved that micrococci and bacilli abound in 

 that petrified peat as they do in modern peats ; he found them abun- 

 dant in bogheads, cannels, lignite and coal. Mycelia of minute 

 champignons are present in the macrospores of Kentucky cannels as 

 well as in wood fragments of coal beds. The close resemblance to 

 peat' conditions led Renault to the conclusion that the plant materials 

 were infected during sojourn in swamps before being swept away by 

 floods, which he believes were extremely violent during Palaeozoic 

 time. 



Conditions during Coal Measures Time were Favorable to 

 Accumulation of Peat. 



Assuming that the writer's conclusions"^ presented on an earlier 

 page are approximately correct, one must regard the Appalachian 

 basin, at the close of the Pottsville, as in great part an irregular 

 plain, raised not far above sea-level and liable to flooding by many 



^^ B. Renault, " Du role de quelques bacteriacees fossiles au point de vue 

 geologique," C. R. Vllle Cong. Gcol. Int., 1901, pp. 646-663. 



'^ " Formation of Coal Beds," III., these Proceedings, Vol. LI., 1912. pp. 



552, 553. 



