group, dating from the same epoch, now on the verge of extinction.
Echinoderms.The sea-urchins (Echinoidea), which date from the Ordovician but attain no great development till the Mesozoic, the starfishes (Asteroidea) and brittle-stars (Ophiuroidea), which also date from the Ordovician, and the sea-cucumbers (Holothuroidea), which appear to be represented in the Carboniferous, do not seem, however, to have attained their full development till the modern period.
That the Annelida are a very ancient group is indicated by the occurrence of remains of marine worms in the Ordovician; while “tracks” or “burrows” apparently point to the existence of the class in the lower Cambrian, if not indeed in the Laurentian.Annelids.
The earliest-known representatives of the Coelenterata occur in the upper Cambrian, where we find primitive types of hydroid polyps, especially the graptolites, which lived only till the Silurian, and have no near relatives. The equally isolated stromatoporids, on the other hand, commenced in the Ordovician and survived till the Devonian. Coelenterates.The corals (Actinozoa) were completely differentiated from the Hydrozoa in the Ordovician. Most of the Palaeozoic actinozoans belong to the Rugosa (inclusive of the four-rayed corals) which did not survive the Permian, but the Aporosa are also well represented. In the Mesozoic and Tertiary as well as at the present day the Aporosa and Porosa became, however, the dominant forms.
As might have been expected from their low grade of organization, the sponges (Porifera) were strongly represented in the early formations; the oldest known form occurring in the Welsh Cambrian. In the Silurian and Carboniferous silicious sponges were extraordinarily abundant, and Sponges.are represented by several extinct groups.
Foraminifera, extremely abundant in the Carboniferous, date at any rate from the Ordovician, where the existing genus Saccammina has been identified. The Chalk consists almost entirely of foraminifers. The Radiolaria, as represented by the Polycystina, are believed to date from the Silurian, or even Protozoa.the Cambrian, but did not attain their maximum till the Mesozoic or Tertiary. The so-called Eozoon of the Laurentian is not admitted to be of organic origin.
Bibliography.—J. A. Allen, “The Geographical Distribution of Mammals,” Bull. U.S. Geol. Survey, vol. iv. pp. 313–76 (1878); F. E. Beddard, A Text-book of Zoogeography (Cambridge, 1895); W. B. Benham, “The Geographical Distribution of Earthworms and the Palaeogeography of the Antarctic Region,” Rep. Austral. Assoc, vol. ix., pp. 319–43 (1903); B. A. Bensley, “A Theory of the Origin and Evolution of the Australian Marsupialia,” Amer. Naturalist, vol. xxxv. pp. 245–69 (1901); W. T. Blanford, “The African Element in the Fauna of India,” Ann. Mag. Nat. Hist., ser. 4, vol. xviii. pp. 277–94 (1876); “Anniversary Address to the Geological Society,” Proc. Geol. Soc. London, 1894, pp. 43–110; “The Distribution of Vertebrate Animals in India, Ceylon and Burma,” Proc. Royal Soc. London, vol. lxvii. pp. 484–92 (1900), and Phil. Trans. R. Soc. (B), vol. cxciv. pp. 335–436 (1901); G. A. Boulenger, “The Distribution of African Freshwater Fishes,” Rep. Brit. Assoc, 1905, 21 pp.; C. Burckhardt, “Tracés Géologiques d'un Ancien Continent Pacifique,” Revist. Mus. La Plata, vol. x. pp. 177–90 (1900); J. D. Dana, “An Isothermal Oceanic Chart, illustrating the geographical distribution of marine animals,” Amer. Journ. Sci. and Art., vol. xi. pp. 153–80 (1853); C. H. Eigenmann, “The Fresh-water Fishes of South and Middle America,” Popular Science Monthly, vol. lxviii. pp. 515–30 (1906); H. O. Forbes, “The Chatham Islands, their relation to a former Southern Continent,” Supplemental Papers, R. Geogr. Soc, London, 1893, pp. 607–37; M. Grant, “The Origin and Relationship of the Large Mammals of North America, Rep. New York Zool. Soc, 1904, 30 pp.; A. Heilprin, The Geographical and Geological Distribution of Animals (London, 1887); F. W. Hutton, “Theoretical Explanations of the Distribution of Southern Faunas,” Proc Linn. Soc. N.S. Wales, 1896, pp. 36–47; T. H. Huxley, “On the Classification and Distribution of Alectoromorphae and Heteromorphae,” Proc. Zool. Soc. London, 1868, pp. 294–319; R. Lydekker, A Geographical History of Mammals (Cambridge, 1896); “South American Animals and their Origin,” Quarterly Review, 1903, pp. 41–67; “The Animals of Africa,” op. cit., 1904, pp. 465–92; C. H. Merriam, “The Geographic Distribution of Life in North America, with special reference to the Mammalia,” Proc. Biol. Soc. Washington, vol. vii. pp. 1–64 (1892); “Laws of Temperature-Control of the Geographic Distribution of Terrestrial Animals and Plants,” Nat. Geogr. Mag., vol. vi. pp. 220–338 (1894); A. E. Ortmann, “The Theories of the Origin of the Antarctic Faunas and Floras,” Amer. Naturalist, vol. xxxv. pp. 139–142 (1901); “The Geographical Distribution of Freshwater Decapods and its Bearing upon Ancient Geography,” Proc. Amer. Phil. Soc, vol. xli. pp. 267–400 (1902); H. F. Osborn. “The Rise of the Mammalia in North America,” Stud. Biol. Laborat. Columbia College, Zoology, vol i. art. 2 (1893); “The Geological and Faunal Relations of Europe and America during the Tertiary period and the theory of the successive Invasions of an African Fauna,” Science, ser. 2, vol, xi. pp. 561–74 (1900); “The Law of Adaptive Radiation,” Amer. Naturalist, vol. xxxvi. pp. 353–63 (1902); A. S. Packard, “The Two Chief Faunae of the Earth,” Science, ser. 2, vol. xix. pp. 220 and 221 (1904), abstract; R. I. Pocock, “The Geographical Distribution of Spiders of the Order Mygalomorphae,” Proc. Zool. Soc London, 1903, vol, i. pp. 340–68; R. F. Scharff, The History of the European Fauna (London, 1899); “Remarks on the Atlantic Problem,” Proc. R. Irish Acad., vol. xxiv. (B), pp. 268–302 (1903); P. L. Sclater. “On the General Geographic Distribution of the Members of the Class Aves.” Journ. Linn. Soc., Zool., vol. ii. pp. 130–45 (1858); “The Geographical Distribution of Mammals,” Manchester Science Lectures, ser. 5 and 6, pp. 202–19 (1874); P. L. Sclater and W. L. Sclater, The Geography of Mammals (London, 1899), B. Spencer, “Summary of the Zoological, Botanical and Geological Results of the (Horn) Expedition,” Rep. Horn Exped. to Central Australia (1896); A. R. Wallace, The Geographical Distribution of Animals (London, 1876), 2 vols.; M. Weber, Der Indo-Australische Archipel und die Geschichte seiner Tierwelt (Jena, 1902), K. A. von Zittel, “Die Geologische Entwickelung, Herkunft, und Verbreitung der Säugetiere,” Sitzberbayer Akad., vol. xxiii. pp. 137–98 (1893). See also C. W. Andrews, Catalogue of the Tertiary Vertebrata of the Fayum (London, 1906); and numerous text-books on various groups of animals, such as A. Günther’s The Study of Fishes (1880), together with works like H. A. Nicholson and R. Lydekker’s A Manual of Palaeontology (London, 1889); K. A. Zittel’s Handbuch der Palaeontologie (Munich and Leipzig, 1876–93), &c. &c. (R. L.*)
ZOOLOGICAL GARDENS, sometimes called Zoological Parks, institutions in which wild animals are kept in captivity. Their primary object is to gratify the pleasure most persons take in viewing at close range the curious and beautiful living products of nature, but they serve also as means of instruction in natural history, providing material for museums and for investigations in comparative anatomy and pathology, while they may have a commercial value as pleasure resorts, or as show grounds for the display of animals that have been imported or bred for sale.
According to Captain Stanley Flower, director of the Zoological Gardens at Giza, Cairo, Egypt, the ancient Egyptians kept various species of wild animals in captivity, but the first Zoological Garden of which there is definite knowledge was founded in China by the first emperor of the Chou dynasty, who reigned about 1100 B.C. This was called the “Intelligence Park,” and appears to have had a scientific and educational object. The ancient Greeks and Romans kept in captivity large numbers of such animals as leopards, lions, bears, elephants, antelopes, giraffes, camels, rhinoceroses and hippopotamuses, as well as ostriches and crocodiles, but these were destined for slaughter at the gladiatorial shows. In later times royal persons and great feudal magnates frequently kept menageries of wild animals, aviaries and aquaria, and it is from these that modern public Gardens have taken their origin. Henry I. (1100–1135) established a menagerie at Woodstock, Oxfordshire, England. This was transferred to the Tower of London, apparently in the reign of Henry III., and kept up there until at least 1828. Philip VI. had a menagerie in the Louvre at Paris in 1333, Charles V. maintained collections at Conflans, Tournelles and in Paris, and Louis XI. formed a menagerie at Plessis les Tours in Touraine, which after his death was re-established at the Louvre in Paris and enlarged by collections obtained in North Africa. It was destroyed by Henry III. Henry IV. had a small collection, which included an elephant. Louis XIII. kept some animals at Versailles, whilst his son Louis XIV. founded the famous “Menagerie du Parc” at Versailles, which received many animals from Cairo, was maintained for over a century, and furnished much valuable material to French naturalists and anatomists. It gradually decayed, however, and was almost extinguished by the mob in 1789. In 1793 the Paris Museum of Natural History was re-established by law, and Buffon’s idea of attaching to it a menagerie was carried out; the latter, as the collection in the Jardin des Plantes, still survives.
In Germany the elector Augustus I. founded a menagerie at Dresden in 1554. In the New World, according to Prescott, King Nezahualcoyotl had zoological gardens at Tezcuco in Mexico in the middle of the 15th century, whilst in the next century Cortes found aviaries and fishponds at Iztapalapan
