564 STEVENSON— FORMATION OF COAL BEDS. LNovember 3, 



in the Falkland islands becomes converted into peat. He saw no 

 moss peat anywhere in South America. Thomson^^ notes that peat 

 in the Falkland islands is very different from that of northern Eu- 

 rope, cellular plants being almost wanting. It is formed for the 

 most part of roots, matted foliage and stems of Empetrum ruhrum, 

 a varietv of " crowberry " common on Scottish hills ; Myrtiis num- 

 mularia, a creeping myrtle ; Caltlia appcndiculata, a dwarf species of 

 water marigold ; with some sedges and sedge-like plants. The roots, 

 preserved almost unaltered, may be traced downward in the peat 

 for several feet, but finally all structure is obliterated and the whole 

 is reduced to an amorphous structureless mass. Mrs. Brassey's^* 

 description of accumulated decayed and decaying vegetation at Borja 

 bay in the Magellan region is in place here, as showing the origin of 

 peat from forest material. 



" To penetrate far inland, however, was not so easy, owing to the dense- 

 ness of the vegetation. Large trees had fallen and rotting where they lay 

 under the influence of the humid atmosphere, had become the birthplace of 

 thousands of other trees, shrubs, mosses and lichens. In fact, in some 

 places, we might be said to be walking on the tops of the trees and first one 

 and then another of the party, found his feet slipping through into unknown 

 depths below." 



But long prior to Darwin, Al. Brongniart^^ asserted that the 

 presence of Sphagnuiii palnstrc is not necessary to the formation of 

 peat. One finds on the banks of the Meuse, below Maestricht, some 

 peats containing only leaves of resinous trees. He contents himself 

 with the observation that all are agreed that, for formation of peat, 

 the essential condition is stagnant water, covering the surface con- 

 stantly and never completely dried up. Lesquereux^" defined peat 

 as a mass of woody plants whose fermentation and, consequently, 

 decomposition were retarded by the presence and the temperature 



''C. Wyville Thomson, "The Atlantic." New York, 1878, Vol. II.. p. 185. 



"Mrs. Brassey, "Around the World in the Yacht Sunbcaiii," New York, 

 1883, p. 128. 



"Alex. Brongniart, " Traite elementaire de mineralogie," Paris. 1807, 

 Vol. II., p. 41. 



^'^ L. Lesquereux, " Quelques recherches sur les marais tourbeux," Mem. 

 Soc. dcs Sci. Nat. Ncuchatcl, Vol. III., 1845, p. 26. 



162 



