. The microscope and its revelations. ral protoplasmicci/closis without the formation of any special • digestive better known forms of this group aretranked under the two generaAcineta and Ilido/iJn-i/a, which are chiefly distinguished by thepresence of a firm envelope or lorica in the former, while the body 784 MICROSCOPIC FORMS OF ANIMAL LIFE of the Litter is naked. In one curious form, the Opliryodendron, thesuckers are borne in a brush-like expansion on a long retractileproboscis-like organ ; and the rare Dendrosoma, whose size is com-paratively gigantic, forms by continuous g
. The microscope and its revelations. ral protoplasmicci/closis without the formation of any special • digestive better known forms of this group aretranked under the two generaAcineta and Ilido/iJn-i/a, which are chiefly distinguished by thepresence of a firm envelope or lorica in the former, while the body 784 MICROSCOPIC FORMS OF ANIMAL LIFE of the Litter is naked. In one curious form, the Opliryodendron, thesuckers are borne in a brush-like expansion on a long retractileproboscis-like organ ; and the rare Dendrosoma, whose size is com-paratively gigantic, forms by continuous gemmation an arborescent colony, of which the individual members remain in intimateconnection with one another. Multiplication in this group seems occasionally to take place bytransverse fission, but this is rare in the adult state. Some-times external genm/n ,-ire developed by a sort of pinching off of apart of the free end of the body, which includes a portion of thenucleus; the tentacula of this bud disappear, but its surface be-. FIG. 598.—Suctorial Infusoria: 1, Conjugation of Podoplirya1quadripa/rtita; 2, formation of embryos by enlargement and sub-division of the nucleus ; 3, ordinary form of the same ; 4, Podo- comes clothed with cilia; and, after a short time, it detaches itselfand swims away—comporting itself subsequently like the internalembryos, whose production seems the more ordinaiy method ofpropagation in this type. These originate in the breaking up ofthe nucleus into several segments, each of which incloses itself ina protoplasmic envelope; and this becomes clothed with cilia, bythe vibrations of which the embryos are put in motion within thebody of the parent (fig. 598, :>), from which they afterwards escapeby its rupture. In this condition (a) they swim about freely, identical with what lias been described by Ehrenberg as a 1*No\v called, after Biitschli, Tokoj>1/rya,on account of its mode of reproduction ;see his 1i-iilozoa, p. litJH.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
