In one of his communications to the Royal Society (April, 1872), on the fossil mammals of Australia, he remarked, touching upon some generalizations suggested by the then present stage of discovery, that "the disappearance of the larger species was explicable on the principle of the 'contest of existence,' as applied by him to the problem of the extinction of the fossil birds of New Zealand ('Transactions of the Zoölogical Society,' vol. iv, 1850), and subsequently by Darwin to the incoming of new species, as 'the battle of life.'" In concluding this paper he remarked that "it is neither creditable nor excusable that so great a divergence should still be maintained, chiefly through theological teaching, in the ideas of the majority of men 'of ordinary culture' as to the cause and conditions of the distribution of living species over the globe from those suggested by the clear and multiplied demonstrations of science." One of his studies in the London clay, in 1873, brought to light the Odontopteryx, a fossil bird, having the peculiarity not found in any existing bird, and one previously unknown in birds, of jaws provided with long, conical, bony processes, like the serrations in a coarse saw.
When he assumed the position to which he was called at the British Museum, Professor Owen's attention was at once directed to the insufficiency of the space the museum afforded for the accommodation of the natural history collections. Repeated representations had already been made on this subject in vain. The Government would not enlarge the provisions at the museum, and finally intimated that it would prefer the alternative of having the collections removed. Professor Owen determined to accept this alternative, and had plans prepared for a large new museum at South Kensington, which would afford a superficial space of five acres to well-arranged collections. The plan was approved by the Government, but did not receive the favor of the House of Commons. Professor Owen then published a pamphlet "On the Extent and Aims of a National Museum of Natural History" (1862). After ten years more of agitation, a parliamentary appropriation was obtained, in 1872, with which the present magnificent range of buildings, now rapidly filling with the nation's treasures of natural history, were erected. "In the obtaining of this splendid casket in which to display Nature's gems," says "Nature," "Professor Owen has seen accomplished one great object of his life." "Nearly a quarter of a century," said the same journal in 1880, "has elapsed since he entered on his duty at the British Museum, and the record of his contributions to science during this period equals, if it does not surpass, that of the previous thirty years' period. Among the more important of these we must notice: 'Memoir on the British Fossil Reptiles of the Mesozoic Formations—Pterodactyles,' 1873-1877; 'On the British Fossil Reptiles of the Liassic Formations—Ichthyosaurs and Plesiosaurs,' 1865-1870; 'On the British Fossil Cetacea of the Red Crag,' 1870; 'On the Fossil Reptiles of South Africa,' 1876; 'On the Classification and