HORNBEAM, HAZEL, BIRCH AND ALDER 101 



in modern winding machines of spools. All of our birches enter 

 more or less into wooden ware, novelty and furniture trades. In 

 Maryland the common river birch (Betula nigra) with wood of 

 modest merit goes extensively into berry baskets. 



For the past sixty years the distillation of sweet birch bark has 

 furnished an oil so similar to that of the true oil of wintergreen, 

 that it has almost entirely superseded the latter where this flavoring 

 is required. Dry distillation furnishes the oil used in tanning 

 Russian leather and to which the latter owes its pleasant odor. 

 In frontier regions the bark of various species furnishes a substitute 

 for paper, and is used more extensively for roofing and for jars and 

 containers — alike by the American Indian for his maple sugar and 

 by the Russian peasant for both liquids and solids. There are 

 great tracts of birch in Russia where this tree is close to the daily 4 

 life of the masses and where its leaves are frequently used for 

 fodder. 



The birches play a considerable part in geological history. As 

 I mentioned in an earlier paragraph there are about 135 extinct 

 species — the earliest known birch-like forms being referred to a 

 genus known as Betulites, of which a score of species and varieties 

 were described by Lesquereux from the Dakota sandstone of 

 Kansas, in which they are present in large numbers. Supposedly 

 similar forms have been recorded from the Upper Cretaceous of 

 Argentina, but these have never been passed upon by a competent 

 botanist and remain doubtful, although the presence of what Dusen 

 calls Betuliphyilum in the early Tertiary of the Straits of Magellan, 

 lends some support to the idea that the ancestral birch stock may 

 have reached South America from the North during the Upper 

 Cretaceous. But if it did it entirely failed to secure a lasting foot- 

 hold on that continent. 



Other Upper Cretaceous birches, referred directly to the modern 

 genus, number 5 or 6 and come from western Greenland, Ne- 

 braska, and western Canada, wood as well as leaves being recorded 

 from the last region. Birches are unknown in the European Cre- 

 taceous, but that they reached that continent early, either from 

 Asia or from the Arctic by way of a North Atlantic land bridge, 



