216 



CHAPTEE IX. 



HEAED ISLAND. 



Diatoms on the Sea Surface. Macdonald Island. Whisky Bay, Heard 

 Island. Coast-line composed of Glaciers. Structure of the Glaciers. 

 Terminal and Lateral Moraines. Glacier Stream. Kocks Cut by 

 Natural Sand Blast. Lava Flow and Denuded Crater. Scanty 

 Vegetation. Kange in Elevation of Arctic and Southern Plants 

 Compared. Mode of Hunting Sea Elephants. Habits of these 

 Animals. Sealers Inhabiting Heard Island. Birds of the Island. 



February 2nd, 1814.— We sailed from Christmas Harbour, 

 whither we had gone at the termination of our survey to 

 erect a cairn with instructions for the Transit of Venus Ex- 

 pedition, on February 2nd, and made for the Macdonald Group, 

 which lies about 240 miles to the south-east of Kerguelen's 

 Land. The channel between the two groups is extremely 

 variable in depth, bottom being found at times in less than 

 100 fathoms, and at others no bottom being obtained in from 

 220 to 425 fathoms. 



The sea surface was full of Diatoms, which filled the towing 

 net in large masses. These masses were found by Mr. O'Meara 

 to be composed mainly of various species of Chaetoceros, with 

 spines of extraordinary length, aggregated in small masses of a 

 jelly-like substance. Occurring with these species of Chostoceros, 

 were representatives of five other genera of Diatoms, three of 

 which were of new species.* 



Heard Island, February 6th, 1874. — On February 6th, after 



beating about for several days in fog, and lying becalmed during 

 one day, we sighted the northernmost island of the Macdonald 

 Group. It was alternately brightened up by sunshine, and 



* Rev. E. O'Meara, M.A., " On the Diatomaceous gatherings made at 

 Kerguelen's Land, by H. N. Moseley." Linn. Journ., Botany, Vol. XV, 

 pp. 56, 57. 



