THE BRYOLOGIST 



Vol. XXIII September, 1920 No. 5 



CONTRIBUTIONS TO ANTARCTIC BRYOLOGY 



H. N. Dixon 



Mosses of Deception Island 



Deception Island is a rarely visited island of the South Shetlands, in Lat. 

 63° S., Long. 60° 30' W., closely adjoining the Antarctic continent (Graham 

 Land). Up to the present century it had been very little visited, and only two 

 plants were known from it. an unnamed moss and a lichen. 



The island is about 5 miles across, and the whole of the interior is formed 

 by a vast crater, into which the sea has irrupted; this is hidden from view ex- 

 cept at the one pomt where this inland sea is connected with the Antarctic Ocean 

 by a narrow channel; the surroundling cliffs are high, steep and rugged, so that 

 until carefully explored it has all the appearance of being a solid mountainous 

 island, instead of being, as it really is, a mere shell of mountain wall surrounding 

 the great sea-filled crater. Hence the name, Deception Island. A full and in- 

 teresting, albeit somewhat weird account of the island is given by Foster in his 

 narrative of the Voyage of H. M. Sloop Chanticleer (1828-30), from the Journal 

 of the ship's surgeon W. H. B. Webster. 



The whole island is nothing more or less than the cone of a gigantic volcano, 

 and traces of activity still remain. The interior of the cliffs, some 1600 ft. high, 

 are scored with small watercourses, arising from springs, the temperature of 

 which is about 185° F., or even higher. A small lagoon is in one place almost 

 cut off from the main interior basin, only communicating with it by a very nar- 

 row outlet; this lagoon is over 200 fathoms in depth, and is partly or entirely 

 filled from the water flowing from the hot springs; its temperature must there- 

 fore be considerably above that of the main body of water, which itself is of a 

 temperature slightly but appreciably above that of the surrounding ocean. We 

 have therefore a condition of things probably unique in phyto-geography, viz., 

 an absolutely isolated area, partly aquatic and partly terrestrial, capable of sup- 

 porting many of the lower forms of life, but one which has been separated from 

 any adjoining regions for what must have been, even geologically, a long period, 

 since the whole of the surrounding area is constantly under perhaps the most 

 severely frigid conditions existing anywhere on the surface of the earth. It 

 seems eminently desirable that the fauna and flora of this remarkable biological 

 preserve should be studied as exhaustively as possible. 



The July number of The Bryologist was published September 17, 1920. 



