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gs； could be clearly enunciated。 Very pleasing is it to read how Darwin； although arriving at a different conclusion to Lyell； shows； by quoting a very suggestive passage in the 〃Principles〃 （1st edition Vol。 II。 page 296。）； how the latter only just missed the true solution。 This passage is cited； both in the 〃Journal〃 and the volume on Coral…reefs。 Lyell； as we have seen； received the new theory not merely ungrudgingly； but with the utmost enthusiasm。
In 1849 Darwin was gratified by receiving the support of Dana； after his prolonged investigation in connection with the U。S。 Exploring Expedition （〃M。L。〃 II。 pages 226…8。）； and in 1874 he prepared a second edition of his book； in which some objections which had been raised to the theory were answered。 A third edition； edited by Professor Bonney； appeared in 1880； and a fourth （a reprint of the first edition； with introduction by myself） in 1890。
Although Professor Semper； in his account of the Pelew Islands； had suggested difficulties in the acceptance of Darwin's theory； it was not till after the return of the 〃Challenger〃 expedition in 1875 that a rival theory was propounded； and somewhat heated discussions were raised as to the respective merits of the two theories。 While geologists have； nearly without exception； strongly supported Darwin's views； the notes of dissent have come almost entirely from zoologists。 At the height of the controversy unfounded charges of unfairness were made against Darwin's supporters and the authorities of the Geological Society； but this unpleasant subject has been disposed of； once for all； by Huxley。 （〃Essays upon some Controverted Questions〃； London； 1892； pages 314…328 and 623… 625。）
Darwin's final and very characteristic utterance on the coral…reef controversy is found in a letter which he wrote to Professor Alexander Agassiz； May 5th； 1881： less than a year before his death： 〃If I am wrong； the sooner I am knocked on the head and annihilated so much the better。 It still seems to me a marvellous thing that there should not have been much； and long…continued； subsidence in the beds of the great oceans。 I wish that some doubly rich millionaire would take it into his head to have borings made in some of the Pacific and Indian atolls； and bring home cores for slicing from a depth of 500 or 600 feet。〃 （〃L。L。〃 III。 page 184。）
Though the 〃doubly rich millionaire〃 has not been forthcoming； the energy； in England； of Professor Sollas； and in New South Wales of Professor Anderson Stuart served to set on foot a project； which； aided at first by the British Association for the Advancement of Science； and afterwards taken up jointly by the Royal Society； the New South Wales Government； and the Admiralty； has led to the most definite and conclusive results。
The Committee appointed by the Royal Society to carry out the undertaking included representatives of all the views that had been put forward on the subject。 The place for the experiment was； with the consent of every member of the Committee； selected by the late Admiral Sir W。J。 Whartonwho was not himself an adherent of Darwin's viewsand no one has ventured to suggest that his selection； the splendid atoll of Funafuti； was not a most judicious one。
By the pluck and perseverance of Professor Sollas in the preliminary expedition； and of Professor T。 Edgeworth David and his pupils； in subsequent investigations of the island； the rather difficult piece of work was brought to a highly satisfactory conclusion。 The New South Wales Government lent boring apparatus and workmen； and the Admiralty carried the expedition to its destination in a surveying ship which； under Captain （now Admiral） A。 Mostyn Field； made the most complete survey of the atoll and its surrounding seas that has ever been undertaken in the case of a coral formation。
After some failures and many interruptions； the boring was carried to the depth of 1114 feet； and the cores obtained were sent to England。 Here the examination of the materials was fortunately undertaken by a zoologist of the highest repute； Dr G。J。 Hindewho has a wide experience in the study of organisms by sectionsand he was aided at all points by specialists in the British Museum of Natural History and by other naturalists。 Nor were the chemical and other problems neglected。
The verdict arrived at； after this most exhaustive study of a series of cores obtained from depths twice as great as that thought necessary by Darwin； was as follows：〃The whole of the cores are found to be built up of those organisms which are seen forming coral…reefs near the surface of the oceanmany of them evidently in situ； and not the slightest indication could be detected； by chemical or microscopic means； which suggested the proximity of non…calcareous rocks； even in the lowest portions brought up。〃
But this was not all。 Professor David succeeded in obtaining the aid of a very skilful engineer from Australia； while the Admiralty allowed Commander F。C。D。 Sturdee to take a surveying ship into the lagoon for further investigations。 By very ingenious methods； and with great perseverance； two borings were put down in the midst of the lagoon to the depth of nearly 200 feet。 The bottom of the lagoon； at the depth of 101 1/2 feet from sea… level； was found to be covered with remains of the calcareous； green sea… weed Halimeda； mingled with many foraminifera； but at a depth of 163 feet from the surface of the lagoon the boring tools encountered great masses of coral； which were proved from the fragments brought up to belong to species that live within AT MOST 120 feet from the surface of the ocean； as admitted by all zoologists。 （〃The Atoll of Funafuti； Report of the Coral Reef Committee of the Royal Society〃； London； 1904。）
Darwin's theory； as is well known； is based on the fact that the temperature of the ocean at any considerable depth does not permit of the existence and luxuriant growth of the organisms that form the reefs。 He himself estimated this limit of depth to be from 120 to 130 feet； Dana； as an extreme； 150 feet； while the recent very prolonged and successful investigations of Professor Alexander Agassiz in the Pacific and Indian Oceans lead him also to assign a limiting depth of 150 feet； the EFFECTIVE； REEF…FORMING CORALS； however； flourishing at a much smaller depth。 Mr Stanley Gardiner gives for the most important reef…forming corals depths between 30 and 90 feet； while a few are found as low as 120 feet or even 180 feet。
It will thus be seen that the verdict of Funafuti is clearly and unmistakeably in favour of Darwin's theory。 It is true that some zoologists find a difficulty in realising a slow sinking of parts of the ocean floor； and have suggested new and alternative explanations： but geologists generally； accepting the proofs of slow upheaval in some areas as shown by the admirable researches of Alexander Agassizconsider that it is absolutely necessary to admit that this elevation is balanced by subsidence in other areas。 If atolls and barrier…reefs did not exist we should indeed be at a great loss to frame a theory to account for their absence。
After finishing his book on Coral…reefs； Darwin made his summer excursion to North