174 



POPULAR HISTORY OF LICHENS. 



wegian mountains, for the manufacture of orchill and cud- 

 bear, under the name of " Norway Rock Moss/' or " Velvet 

 or Velutous Moss." Spermogones are abundant on some 

 varieties, roughening the pale surface of the thallus with 

 their minute, conical black tubercles, which are either 

 grouped towards its periphery or irregularly scattered ; they 

 are immersed, very dense and easily sectioned, regularly 

 ellipsoid in figure, having a simple cavity. The sterigmata 

 are articulated, ramose, and solid ; spermatia very fine and 

 straight. In other species the spermogones are less easily 

 recognized by the naked eye, from the darker colour of their 

 thallus. Like most of its co-species, it grows chiefly on 

 granitoid rocks, on very high mountains, or in Arctic and 

 sub-Arctic regions. On the Mexican volcano of Orizabo it 

 occurs at a height of between 13,000 and 14,000 feet, along 

 with other species. It is one of the Umbilicarias which 

 constitute the "Tripe de Roche " of sub-Arctic America and 

 the Polar regions. This black, leathery, forbidding-looking 

 " Rock Tripe " is often boiled and eaten by the Canadian 

 hunter w T hen pressed by hunger ; in Iceland it is frequently 

 eaten in periods of scarcity as a supplement to the more nu- 

 tritious "Iceland Moss/' and it has been repeatedly men- 

 tioned in the narrative of Polar voyages as having been the 



