344 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1908. 



continuous daylight of summer. That dense foliage grows upon the 

 moraines of Alaska is Avell known from the photographs, taken upon 

 the Malaspina Glacier, published by I. C, Russell ; "' and in the same 

 district forests of fir trees, groAving on moraines, are being now trans- 

 ported by the Alaskan glaciers. 



The fossil tree trunks in arctic coal seams would supply better evi- 

 dence of a change of climate than the fossil leaves, if there w^ere 

 evidence to prove that the trees had grown in situ. The view that the 

 three months' darkness of winter would be fatal to tree growth is now 

 recognized as untenable; but it is a fact that forests do not occur 

 north of 70°, although fossil tree trunks have been found beyond that 

 latitude. But these tree trunks were probably carried north as drift- 

 wood.. 



Robert Brown has described the Disco plant beds and come to the 

 definite conclusion that the plants had not grown in situ. Baron 

 von Tol has published photographs of plant beds associated wdth 

 ancient ice in northern Siberia, but his photographs show the roots 

 of nothing larger than shrubs. In 1896 I had occasion to mine some 

 hundredweights of coal from the seam of Advent Bay, Spitsbergen 

 (latitude 78° 15' N.), and the section exposed gave no evidence that 

 the coal had been formed from vegetation that had grown in situ. 



In many places the arctic shores are white Avith a litter of pine, 

 fir, and larch logs, which have been floated down the Siberian rivers, 

 drifted across the Arctic Ocean, and been thrown upon the shores.^ 

 These accumulations of driftwood become covered by the growth of 

 moss, saxifrages, and arctic willows; and if then buried beneath 

 sheets of sediment would form arctic coal seams, made from timber 

 that had groAvn in central Asia. 



The i^aleobotanical evidence that the arctic regions had a tropical 

 or subtropical climate in the Cretaceous is inadequate, and it is con- 

 tradicted by the Paleozoological evidence of the contemporary marine 

 deposits. The Cretaceous marine beds in Greenland have a stunted 

 fauna, Avhich has no tropical or subtropical characters. The British 

 Chalk sea was sufficiently cold for drift ice to carry boAvlders as far 

 south as London and its fauna is decidedly nontropical. The Chalk 

 sea was of moderate depth, but its crinoids were small and scarce, its 

 corals. Avere small and simple, and its mollusca indicate a cooler sea 

 than do the Hippurites^ etc., of the Mediterranean beds. In the 

 Lower Cretaceous beds of British Isles there are abundant shalloAV 

 sea and shore deposits, but there are no coral reefs, and the general 

 aspect of the fauna indicates a sea decidedly colder than that of the 



«I. C. Russell, "Second expedition to IMoiint St. Elias," TliirtooiUb Ann. Rop. 

 U. S. Geol. Sui-v., 1893, PI. XIV. 



^A photograph showing one of these finiber-slrewn beaches has been pub- 

 lished in the " Voyage de la Manche," PI. V, 1894. 



