identity, till at last in sounding for a longer disappearance and a
greater depth than usual, the hinder third of the enormous beast appeared
above the surface for the first time with its little angular dorsal fin,
at once dispelling any doubts we might have had."[70]

It is supposed to be the largest mammal that has ever existed.[71] As it
comes up to blow, "one sees first a small dark hump appear and then
immediately a jet of grey fog squirted upwards fifteen to eighteen feet,
gradually spreading as it rises vertically into the frosty air. I have
been nearly in these blows once or twice and had the moisture in my face
with a sickening smell of shrimpy oil. Then the hump elongates and up
rolls an immense blue-grey or blackish-grey round back with a faint ridge
along the top, on which presently appears a small hook-like dorsal fin,
and then the whole sinks and disappears."[72]

To the biologist the pack is of absorbing interest. If you want to see
life, naked and unashamed, study the struggles of this ice-world, from
the diatom in the ice-floe to the big killer whale; each stage essential
to the life of the stage above, and living on the stage below:

THE PROTOPLASMIC CYCLE

Big floes have little floes all around about 'em,
And all the yellow diatoms[73] couldn't do without 'em.
Forty million shrimplets feed upon the latter,
And _they_ make the penguin and the seals and whales
Much fatter.

Along comes the Orca[74] and kills these down below,
While up above the Afterguard[75] attack them on the floe: