22 NOVEMBER 1930, Page 51

Coral Architects

A Year on the Great Barrier Reef. By C. M. Yonge. (Putuam4 21s.)

THE oddity of Australian animals (whose evolution is indeed unique) is in some measure repeated in the structure of the country. Certainly there are not six other wonders in the world to rival the Great Barrier, those thousand and more miles of coral reef, deep and broad, that defend the coast of Queensland from the surges of the Pacific. And when we endeavour to probe and plumb one wonder we usually drive more wonders into the open. Now one of the last acts of Russia Before the Revolution Sir Matthew Nathan, one of the wisest Governors ever sent to Australia, was to fuither the scheme for sending a group of biologists and other men of science to study the nature of this Reef, and especially its makers and inhabitants. Mr. Yonge's record, made visible by a hundred photographs and diagrams, would be described in a lower class of letters as a thriller. It may almbst challenge comparison with that classic, The Voyage of the Beagle, or Seebohm's first account Of Siberia. Mr. Yonge, part author of The Seas, is a marine biologist of great accomplishment, and happily possesses no mean gift as a popular exponent. Cairns, the base of the expedition, is a place by itself. As you journey north towards it, the country grows more tropical with every yard. Common farm crops give place to sugar, bananas, pineapple and what not. At last at the Cairns terminus you come up against a tropical forest that Northern Brazil might regard as typical.

But the sea is yet more wonderful than the land. On the edge are many of those queer nightmare formations known

as mangrove swamps, where seeds germinate while growing on the trees and roots make mazes with their aerial pillars and tangled branches. Further out comes the calm and Colour and quiet mystery of the coral, which has shared with volcanic energy the task of creating most of the South Sea islands, and itself added to their incommunicable romance. The anemone, to which race the coral-makers belong, has so Mighty an assessor in the inorganic world.

Is there any book that gives so good an account of what coral is, how coral comes—and goes—and how it is inhabited ? The Barrier Reef is much the greatest and strangest of all coral formations. Captain Cook himself gave a wonderful account of experiences behind it, and many investigators, scientific and geographic, have continually increased our knowledge ; but Mr. Yonge has taken a different angle Or investigation from most of his predecessors ; and though he spent no more than a short year, had peculiar facilities. He has coped a really marvellous summary of accumulated knowledge with individual research in a book that lie who runs may read. To this he has added some lively account of Thursday Island, head of the mother-of-pearl fisheries.

• The coral-making anemone builds what may be called a key industry. The marvel only begins, as research now proves, with the manufacture of the coral itself, which is of many sorts and colours. The little creature secretes lime as a skeleton, and gives it as lovely forms and colours as a flower. It enjoys a curious symbiosis, if the word be allowed, with a minute weed of the sea, which helps the live creature only less than it helps itself. The coral becomes a real concrete wall by the aid of plants, protozoa and inorganic accretions, all_ three. In making artificial concrete one of the first essen- tials is to wash the grit or gravel clean enough. This is equally necessary to coral, and a good deal of this work is done merely by the waving of the minute cilia or fringes waved by.. the tiny animal. The destructive forces, animate and in- animate, which may destroy a coral reef, as eruptions destroyed the Pink terraces in New Zealand, make in themselves a tale of marvel ; and their investigation has led to descriptions of such adjacent monsters as the great cockles—to use Captain Cook's name—sometimes over four feet across, which have killed those inadvertently nipped in their shells. For those particularly interested in birds the book has not the charm of, say, Beebe's account of the strange Galapagos island.; ; but there is one stirring account, and photograph, of the Sooty Terns, of the Wide-awakes and the Noddies that overwhelm one island with eggs and young in season, and with noise, smell and bird-lice out of season. There search was essentially sub- marine ; and after all, beche-de-rater—both in its natural history and the history of its use—is a more interesting product than guano ! The narrative is not without its personal drama : it moves up the coast as far as the islands of the Torres Strait ; 'and Mr. Yonge finishes with a general, but attractive sketch of the Isles of the Pacific as a whole, and such supermarine -denizens as the Polynesians who inhabit Fiji, Samoa and even 'New Zealand. The British Association, which backed the `cipedition, has done as much in this instance for popularizing 'science (which is its proper function) as for the original research -that it is enabled to encourage and subvent. -

THOMAS. .