602 STEVENSON— FORMATION OF COAL BEDS. [November 3. 



from Bradley's"-^ notes on the disappearance of meadows which 

 were used as camping places in the Sierra Nevada. Fifteen years 

 ago, these were open and covered with abundant grass. Originally, 

 they were ponds or lakes which became filled with peat, on which 

 grass thrived. As the material became less wet, tamarack seeds, 

 blown in from the border, took root, but the young shoots were 

 killed by the frequent fires. Since protection against fire has be- 

 come complete throughout the region, the tamarack has advanced 

 so as to occupy much of the surface, while pines are encroaching, 

 which eventually will crowd out the tamarack and will occupy the 

 whole area. The trees are rooted in the peat. 



Bates"" has shown that swamp conditions and luxuriant growth 

 of trees are not incompatible. In describing the forests of Para, 

 he says that one swampy area was covered with trees more than 100 

 feet high, all of second growth. In another swamp, the air was 

 marked by a mouldy odor, the trees were lofty and the surface was 

 carpeted with lycoi)odiums. Farther down in this area, where the 

 ground was more swampy, wild bananas, great palms and exogens 

 grew luxuriantly and were covered with creepers and parasites; 

 while the surface was encumbered with rotting trunks, branches, 

 leaves, and the whole was reeking with moisture. Kuntze, already 

 cited, states that the tropical swamps are densely wooded. Obser- 

 vations by other authors will be referred to in another connection. 



Peat Deposits in Europe. — The importance of peat as fuel in 

 Europe has led to thorough investigation of that material from every 

 conceivable standpoint. The literature is so extensive and, in great 

 part, so excellent that one, compelled by limits of space, finds him- 

 self embarrassed in selection of authors as well as of matter. 



Lesqucreux"* long ago proved that Spliayniiin is not the impor- 

 tant factor in peat-making; he recalled attention to Ad. Brongniart's 



"'" H. C. Bradley, "The Passing of Our .Mnuntain Meadows," Sierra 

 Club Bull., Vol. VIII., 191 1, pp. 30-42. 



"^ H. W. Bates, " Tlie Naturalist on tlie River Amazons," London, 1863. 

 Vol. I., pp. 44, 47, 50, 51- 



"' L. Lesquereux, " Quel(|ucs reclierches sur les marais tourheux," pp. ;^2, 

 III, i2r, 137; 2d (}eol. Surv. Penn., Rep. for 1885, pp. 107-121. 



200 



