FLORA. 165 



forms are wonderfully varied ; so that they present to the 

 student of Nature an almost inexhaustible field of inquiry. 

 In their most rudimentary aspects they seem to consist of 

 nothing more than a collection of powdery granules, so 

 minute that the figure of each is scarcely distinguishable, 

 and so dry and so deficient in organisation that we cannot 

 but wonder how they live and maintain life. Now they 

 are seen like ink-spots on the trunks of fallen trees ; now 

 they are freely sprinkled in white dust over rocks and 

 withered tufts of moss ; others appear in gray filmy patches ; 

 others again like knots or rosettes of various tints ; and 

 some are pulpy and gelatinous, like aerial sea-weeds which 

 the receding tide leaves bare and naked on inland rocks. 

 A greater complexity of structure, however, is visible in 

 the higher order of lichens and we find them either 

 tufted and shrubby, like miniature trees ; or in clustering 

 cups, which, Hebe-like, present their " dewy offerings to 

 the sun." 



' In the Polar world, and its regions of eternal winter, 

 where snow and ice, and dark drear waters, huge glacier 

 and colossal berg, combine to form an awful and impressive 

 picture, the traveller is thankful for the abundance of 

 these humble and primitive forms, which communicate the 

 freshness and variety of life to the otherwise painful and 

 death-like uniformity of the frost-bound Nature. 



' A lichen which is discovered in almost every zone of 

 altitude and latitude, which ranges from the wild shores of 

 Melville Island in the Arctic to those of Deception Island 

 in the Antarctic circle, which blooms on the crests of the 

 Himalayas, on the lofty peak of Chimborazo, and was 

 found by Agassiz near the top of Mount Blanc, is the 

 Lecidea geographica, a beautiful bright-green lichen, whose 

 clusters assume almost a kaleidoscopic appearance. 



' A lichen of great importance in the Arctic world is the 

 well-known Cladonia rangiferina, or reindeer moss, which 

 forms the staple food of that animal during the long Arctic 

 winter. In the vast tundras, or steppes, of Lapland, it 

 flourishes in the greatest profusion, completely covering 



