27. 
The South Australian Naturalist. 
scopic, and was known as plankton. Investigation had shown 
that the life of the sea varied in character with depth, and was 
100 
grouped in zones. Cuttlefish were prolific from 50 to 
fathoms. As the depth increased the fish became phosphorescent. 
Dredging in the deep sea involved many technical problems, and 
required great skill and experience. Sometimes half a ton of 
living creatures, many of minute size, would be obtained in one 
haul. It was found that red predominated in deep-sea colouring, 
the v/ater quickly filtering out the blue. At the greatest depths 
there was no colour. Below a depth of 2,500 fathoms magnetic 
particles were found in the red clay, and it was probable that 
they were of extra terrestrial origin (particles of meteorites). 
j, Macquarie Island shores were characterised by deposits of 
,j. seaweed the stems of which were as thick as a man’s leg. It has 
^ remained unchanged in spite of the many visits paid to it by whal- 
ers and sealers. It was too small to have permanent ice, and all 
snow was thawed wdthin a week or two of its fall. Though the 
hilltops Avere bare, tussock grass grew thickly, and there was 
herbage of various kinds. The smooth outline of the hills gave 
evidence of former glaciation. All the seal and bird 
life of the Southern Ocean resorted to that island, so that it was 
important to reserve it as a sanctuary. The leopard seal was 
the only predaceous one on the Southern Hemisphere, and would 
.attack and eat other seals. It was unfortunate for the elephant 
seal that it yielded blubber, the demand for the oil from which 
din TVl ^termination. The sealers nowadays boiled 
Sv indiscriminately. 
^ n;f2’ r government had placed an embargo on the 
oil industry, by forbidding the killing of those creatures 
On the voyage south from Macquarie Island icebergs were 
hHadoVsl? n^elted plain marks on the sides showed 
e / dissolution proceeded. The largest 
erg seen by the Mawson expedition was 210 feet high In the 
“pE',7TT.‘" 
reach most nf ^ • pmntitul. It was impossible to 
l»r “or*f.nce ‘"'r"' ‘‘"P' 
as much as 186 m'l snouts of glaciers protruded 
in ZX l and the Great Ice Barrier 
«cept during a thaw Tl ff out i am, and there was no water 
everything appea , ink Hr A nmke 
anydistanceC the i : ^"y^'°gether. There was no life at 
of 8«a, lateres ,0 ;ilTploSf 
