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: 
And if a sailor tumbles in and stoves the mushy pack in,
He’s crumpled up between the floes, and so they get
Their whack in.

Then there’s no doubt he soon becomes a Patent Fertilizer,
Invigorating diatoms, although they’re none the wiser,
So the protoplasm passes on its never-ceasing round,
Like a huge recurring decimal ... to which no
End is found.[76]

We were early on the scene compared with previous expeditions, but I do not suppose this alone can explain the extremely heavy ice conditions we met.  Possibly we were too far east.  Our progress was very slow, and often we were hung up for days at a time, motionless and immovable, the pack all close about us.  Patience and always more patience!  “From the masthead one can see a few patches of open water in different directions, but the main outlook is the same scene of desolate hummocky pack."[77] And again:  “We have scarcely moved all day, but bergs which have become quite old friends are on the move, and one has approached and almost circled us."[78]

And then without warning and reason, as far as we could see, it would open out again, and broad black leads and lakes would appear where there had been only white snow and ice before, and we would make just a few more miles, and sometimes we would raise steam only to suffer further disappointment.  Generally speaking, a dark black sky means open water, and this is known as an open-water sky; high lights in the sky mean ice, and this is known as ice-blink.