THE SUB- ARCTIC ZONE. 43 



Island, about 64 12' south latitude, due south of Cape 

 Horn. Vegetation does in truth reach its last limit here, 

 as nothing but Mosses arid Lichens are to be seen. Cock- 

 burn Island is a barren rock :* "on approaching it, the 

 cliffs above are seen to be belted with yellow, which, as it 

 were, streams down to the ocean, among the rocky debris. 

 This appearance was found to be entirely owing to the 

 abundance of a species of Lichen (Lecanora miniata). 

 Mosses grow in the soil which is harboured in the fissures 

 of the rocks ; they are excessively minute, the closest 

 scrutiny being requisite to detect them ; and so hard frozen 

 into the ground, that they could not be removed without a 

 hammer. Three of the Mosses are likewise European, Tor- 

 tula gracilis, T. l&mpila, and Bri/um argenteum, which is 

 also Arctic. The flora of Cockburn Island contains nine- 

 teen species, all belonging to the Orders Mosses, Alga3, and 

 Lichens." Over the solitude of this island reign unmo- 

 lested, penguins and cormorants, and the beautiful white 

 petrel, whose nest, consisting only of a few feathers, is built 

 on the bare and precipitous cliffs. 



* From Sir James Ross's Antarctic Voyages. 



