. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. turns inwards, forming a spiral fold around a funnel-like aperture (fig. 8) which leads to the mouth, and likewise lodges the orifice through which digested materials are cast out. The currents caused by the marginal fringe around the disc are all directed towards the oral aperture, and consequently, by bringing nutritive particles to the mouth, this part of the apparatus becomes eminently subservient to nutrition. In several species of Stentor, in addition to the apparatus of cilia described above, there is an additiona
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. turns inwards, forming a spiral fold around a funnel-like aperture (fig. 8) which leads to the mouth, and likewise lodges the orifice through which digested materials are cast out. The currents caused by the marginal fringe around the disc are all directed towards the oral aperture, and consequently, by bringing nutritive particles to the mouth, this part of the apparatus becomes eminently subservient to nutrition. In several species of Stentor, in addition to the apparatus of cilia described above, there is an additional riband-shaped band of these vibratile organs extending from near the mouth to a considerable distance towards the hinder part of the body, the outline of which has an undulated appearance. The Trichodinae, or Urn animalcules, have no pedicle or elongated tail, but are provided with a fasciculus or circlet of cilia situated in front of their bodies, which are disc-shaped, bowl-shaped, or conical, the mouth being ap- parently a single orifice situated in the ciliary circlet. One species of this group, T. pedicu- kis, seems to be parasitically attached to the Hydra viridis, and allied forms have been met with in the respiratory laminee of several bi- valve shell-fish, (Anodonta, Unto, &c.,) and also in Gyrodactylus coronatus, itself a parasite inhabiting the gills of the Crucian Carp fCy- prinus Caras&ius). That these animalcules are really Polygastrica, and not sterelminthous en- tozoa, Ehrenberg satisfied himself by feeding them with indigo. Urocentrum seems to be similarly organized, only it is furnished pos- teriorly with a sharp style-like process. But perhaps the most remarkable as well as most elegant of all the forms of animalcules belonging to this group are the Vorticcllte, Cfig-9,} the sight of which cannot fail to exact the untiring admiration of the microscopical. Stentor Roeselii, highly magnified, t, viscus supposed by Ehrenberg to be the testis. Vorticdl
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