286 THE ANTARCTIC MANUAL, 
teristic fishes, the corals, siphonophores and go forth, that markedly 
distinguish the tropical seas; on a slightly closer inspection it is 
equally plain that many prominent genera and larger groups—the 
genus Serolis, the peculiar Trachinoid fishes for example—are charac- 
teristic of the Antarctic and sub-Antarctic waters, and of these alone: 
But is the residuum only what is common to, or something built upon 
what is common to, all seas; or does it date back to the conditions 
of a past epoch, to a fauna that was once common to all seas but 
is now left only at the extremes of the earth and is obliterated 
between? It has been maintained by some that this latter is the 
case; that there is a common bipolar fauna non-existent in the 
tropics, and even that hundreds of species in the Arctic and Antarctic 
fauna are identical one with another. This view is contested by 
others, and I for my part do not share it. But on this question 
more argument ig much less to be desired than more investigation. 
For, even supposing the specific identity of so many forms to be 
disproved, it may be that there remains sufficient ground for a 
similar deduction from the general affinities of the rest: or, on the 
other hand, if the inference be wholly false, we may find resem- 
blances which are not original, but which throw light on questions 
of variation and evolution under similar conditions. 
We have also minor problems of distribution subordinate to this 
greater one ; for instance, the relation of the common Antarctic fauna 
to the several faunas of the Atlantic and the Indo-Pacific, and in 
particular—as has been said above—to that fauna that would seem 
to go, as the Macrocystis goes, along the comparatively cold shore- 
waters of Western America to Behring Sea. 
While the zoological exploration of the Antarctic needs neither 
defence nor further recommendation, I cannot help adding, ere I 
conclude, that I think all British zoologists must be the more anxious 
that their science should reap a harvest from the forthcoming 
Expedition, from a feeling that for years past our country has been 
outstripped in such work by others. Since the pioneer expeditions 
of the Porcupine and their great outcome the Challenger expedition, 
oceanic zoology would have been almost in abeyance with us, had it 
not been for Dr. Alcock’s most productive researches in the Bay of 
Bengal ; while on the other hand, expedition after expedition has been 
sent out by French and Germans, Americans and Scandinavians. All 
our experience teaches us that the fauna of the deep sea may be 
treated as practically inexhaustible for a long time to come. The 
dredge never comes up without new treasures. The eight hauls made 
by the Challenger in the deep waters of the Kerguelen region furnished 
