I9II] STEVEXSOX— FORMATION OF COAL BEDS. 565 



of water. \'ogt,^" while giving pre-eminence to Sphagnum, notes 

 that under favorable circumstances any vegetable substance can be 

 converted into peat, for some peats are formed of grasses and reeds. 

 Heer^^ assigns to mosses only a subordinate part and asserts that 

 peat originates partly from mosses, partly from water-plants, from 

 swamp plants, especially from grasses and sedges, and partly from 

 woody plants. A. Winchell in i860 and Grand'Eury in 1882 made 

 the conditions equally clear, w^hile Friih^'-' showed that Sphagnum is 

 a late arrival in accunuilation of peat. 



Peat in the Tropics. — The belief prevails that peat is not pro- 

 duced in the tropics. Jameson,''** long ago, asserted that peat is 

 peculiar to cold climates, but not wholly so, for Anderson had re- 

 ceived some from Sumatra. It is quite natural to find peaty sub- 

 stances in warm climates for peat at the bottom of a mountain is 

 more decomposed than that at the top ; that of southern England 

 more than that of north Scotland; that of France is more coalv than 

 that of England, while no peat is found in the French lowlands 

 except under cover. All of which shows that decomposition in- 

 creases toward warm climates, until, in the tropics, it is so rapid 

 that masses of peat cannot form. 



Fruh^^ was unwilling to believe that true peat forms in the 

 tropics. He discusses a great number of reported occurrences in 

 tropical and sub-tropical areas. For him, the observations are in- 

 complete and his conclusions are that, so far as known, there is no 

 important deposit of true autochthonous peat in the lowlands of the 

 tropics ; that, within the tropics, formation of peat is in elevated 

 regions, where the climate is that of the temperate zone ; that the 

 supposed peat layers, bored through in the alluvium of great trop- 

 ic. Vogt, " Lehrbuch der Geologic," 2d Aufl., Braunschweig, 1854, Vol. 

 II., p. no. 



°^ O. Heer, " Die Schieferkohlen von Utznach und Diirnten," Zurich, 

 1858, pp. 1-4. 



^°J. J. Friih, " Ueber Torf und Dopplerit," Trogen, 1883. 



*^R. Jameson, "An Outline of the Mineralogy of the Shetland Islands, 

 and of the Island of Arran," Edinburgh, 1798, pp. 151-153. 



" J. J. Friih und C Schroter, " Die ]Moore der Schweiz," Bern, 1904, 

 pp. 134-143- 



163 



