d
the problem is to account for this distribution. Many forms of plant and
animal life are circumaustral, being found in all suitable sub-antarctic
situations. To account for this fact two theories have been advanced,
namely, the Relict theory (Dahl, Schenck and others) and the Antarctic
theory.

The first theory supposes that the inhabitants of the sub-antarctic
islands are the remnants of groups of animals developed in some northern
land-mass, and driven south by more highly developed forms. Again, that
these sub-antarctic islands have always been separated from continents,
and that the distribution of life on the former must have proceeded over
wide stretches of sea.

The Antarctic theory accounts for the distribution and similarity of
sub-antarctic fauna and flora by establishing a connexion between the
sub-antarctic islands and the Antarctic continent. At the same period,
the Antarctic continent was assumed to be connected by land with South
America, South Africa and Australia, and the similar life forms now
found in these continents were driven northward by a subsequent colder
period. This theory is strengthened by several facts, chief of
which are, (1) the existence of an Antarctic continent, and (2) the
comparatively shallow waters between it, South Africa, Australia and
South America.

Whichever theory is adopted, it is evident that our scientific
opportunities were unique.

On the 28th, Sandell, Sawyer and I decided to climb on to the main ridge
or plateau of the island. We had already discovered that the easiest
way to get on to the hills was to follow up one of the many ravines or
gullies which run down to the sea. This necessitates walking in water
most of the way, but one soon gets accustomed to wet feet on Macquarie
Island.

The slopes rise in a series of terraces which are generally soggy and
covered with tussock (pleurophyllum) and with scattered cushions of
Azorella. The summit of the ridge is a barren waste, over which loose
rocks are scattered in every direction, while a wavy effect due to the
action of wind is plainly visible over the surface of the ground. The
steep, descending sides are very soft and sodden, supporting a scanty
growth of vegetation, including the small burr known as the "biddy-bid."

Hundreds of tarns and lakes are visible along the plateau-like ridge
which extends throughout the length of the island. Several of the lakes
are half a mile long and very deep. The tarns are,