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Show 392 POLYPI. substance but a diaphanous parenchyma filled with more opaque granules. Notwithstanding this, they swim, crawl, and even walk by alternately fixing their two extremities in the manner of Leeches or of the caterpillars called Geometrre. They agitate their tentacula and use them for seizing their prey, which can be seen being digested in the cavity of their body. Tl}ey are sensible to the action of light and seek it, but their most wonderful property is that of being· constantly reproduced by the indefinite excision of their parts, so that we can multiply them at will by means of division. Their natural increase is by shoots which push out from various points of the body of the adult, and at first resemble branches. Five or six species, all differing in colour and the number and proportion of the tentacula, are found in stagnant waters in France. One of them, H. viridis, Tremb., Pol., I, 1; Rces., III, lxxxviii; Encyc., LXVI, is of a beautiful light-green. It is particularly common under the leaves of the Lemnre, and has been rendered celebrated as the first species on which the experiments relative to the reproductive power of the genus were essayed. The H. fusca, Tremb., Pol., I, 3, 4; Rces., III, lxxxiv~ Encyc., LXIX, is more rare, and of a grey colour. Its body is not above an inch long, and its arms are ~ore than ten( 1 ). CoRINE, Grert. The Corines have a fixed stem terminated by an oval body, of a firmer consistence than that of the Hydrre, open at the summit, and completely covered with little tentacula. Some of them carry their ova at the inferior part of the body(2). (1) Add Hyd. gri&ea, Trembl., 1, 2; Rces., ill, lxxviii-lxxxiii; Encyc., LXVll; -Hyd. pal'lem, Ra:s.; llJ, lxxvi, lxxvii; Encyc., LXVIli;-Hyd. gelatirwsa, Zool. nan., cxv, 1, 2. N.D. The ten first Hydrae of Gmelin are :Actiniae, and the eleventh-H. dolio· lum-a Holothuria. (2) 'l'ubularia C()'l"gna, Gm.; or Coryne pusilla, Gaert., App. Pall. Spicil., X, iv, 8; Encyc., LXIX, 15, 16;-Tubulariaa.ffinis, Gm.; Pall., lb., 9; Encyc., Ib., 14;Hydra multicornis, Forsk., XXVJ, B. b; Encyc., lb., 12, 13;-Hyd. &quamata, MUll., Zool. Dan., IV; Encyc., lb., 10, 11;-and the species sketched by Bose., Hist: des Vers,ll, pl. xxii, f. 3, 6, 7, 8. N.B. The genus Corine, which I have not observed myself, appears to merit re-examination. GELA T INOSJ, 393 CniSTATELLA, Cuv. Where there is a d ou bl e range of nu mouth, curved into a h If . merous tentacula on the h . h a moon, formmg 1 w IC attracts the nutrit' a p ume of that figure These mouths are placed .Iou~ molecules by their regular motion' Iatinous body which p on s lOI~t necks attached to a common ge. . rogresses m the f - ammals are found in st . manner o a Hydra. These h agnant waters m F t ey seem to be small spots of mould( 1 ). ranee. To the naked eye VORTICELLA. Whhe rbe the stem is fixed ' f requently ramou d eac ranch terminating by a bod sha . s an much divided, the aperture project two o . y ped hke a bell or horn. From I · pposmg groups of fil . stant y m motion and th t . . aments which are con- ' a attract nutrltious 1 1 are very numerous in fresh wate mo ecu es. The species perceived without J. m' r, and are generally too small to be 1 p Icroscope They £ b umes, &c. &c.( 2 ) • orm ushes, arbuscles, PEDICELLARIA. The Pedicellarire are found betw . considered by various auth een the spmes of the Echini, and are bably however they are Po1oyrsi a~~:gans of these animals; most proconsist of a long slender ste! ' h'Ich ther~ seek an asylum. They ed at I· ts extremity with tenta·c 'u lwa Ich ter. mmates b y a h orn, furnish-foliaceous( 3). ' sometimes filiform and sometimes (1) Cristatella mucedo Cuv . R . (2) 'lfh ' ·' res., III, xct e only species I refer to th. . pl. XXIV and XXVI Th Is genus are those figured in th E species placed among. the;! are cl?sely united by strong affinities w'th ncy~., (3) M"ll Z tcroscoptcal animals. 1 certam u ., ool. Dan XVI . V ., 'cop1ed Encyc. LXVI OL. IV.-2 z ' . |
