1893. NOTES AND COMMENTS. 243 
Tue GREAT BARRIER REEF OF AUSTRALIA. 
In our issue for November, we called attention to the work of 
Mr. Saville Kent on the Great Barrier Reef, and were enabled, 
through the courtesy of Messrs. W. H. Allen & Co., to give a speci- 
men plate from his remarkably interesting book. We have now 
received from the publishers a set of twelve beautiful enlargements 
in permanent photography that have been prepared for the use of 
Museums and Natural History Societies. These pictures, which 
measure 15 ins. by 11 ins., show, in a striking manner, the appearance 
of a coral reef at low water, and, in many instances, even the generic 
relation of the coral masses can be determined. From a geological 
or zoological point of view, these photographs will be invaluable. 
They are published, ready mounted for framing, at half-a-guinea 
each, or four guineas for the twelve. 
DREDGING ON Rocky GROUND. 
So much has been written about our knowledge of the deep-sea 
and its inhabitants, that it is scarcely realised how little we do know. 
We let down a dredge or trawl at haphazard into the dark, and scrape 
off certain of the creatures that are to be found on the surface of the 
muddy bottom ; but of those that bore deeply we have no knowledge. 
On rocky or stony ground we have not even these small opportunities 
for learning what creatures live there, except the few that may be 
brought up by the hempen tangles; yet in all probability it is on the 
irregular rocky bottom, rather than on the monotonous mud flats, 
that life is the most varied. 
If we want to obtain some measure of the extent of our ignorance, 
we must put ourselves in the place of the inhabitants of the deep-sea. 
Let us imagine some dwellers in upper air to be anxious to learn 
what sort of creatures are to be found in its lower strata, or crawl 
about on the earth’s surface, beneath the mantle of cloud and fog. 
An exploring balloon is sent out, with instructions to dredge carefully. 
The first haul is made in the dark on rocky ground—say among the 
houses of London. What would be the result? The dredge would 
leap from roof to roof, missing the varied life of the streets below. 
It would bring up some slime out of the gutters, a tangled mass of 
telegraph wires, some weather-cocks and ventilators, broken chimney 
pots, a stray cat or two, and perhaps a casual burglar with his lumi- 
nous apparatus. 
The scientific men of upper air, asked to report on the haul, 
would remark on the wonderful advance that had been made in the 
knowledge of the deeper air, and of the customs of its inhabitants. 
They would reconstruct in imagination the world below, and would 
probably suggest that telegraph wires and chimney-pots are the 
snares and traps used by burglars for the capture of cats. 
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