Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 CILIATA. ID!) one or more rings of large cilia round the edge of a raised lid- like flap which is capable of being shut down. There is also an in- ferior row of cilia upon this flap running to the mouth. The free-swimming Infusoria often possess in addition to these delicate cilia and zones of cilia, thicker hairs and stiff bristles, and more or less bent hooks, which are em- ployed in locomotion and for attachment. Certain fixed Infusoria as Stentor (fig. 138) and Cothumia secrete ex
Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 CILIATA. ID!) one or more rings of large cilia round the edge of a raised lid- like flap which is capable of being shut down. There is also an in- ferior row of cilia upon this flap running to the mouth. The free-swimming Infusoria often possess in addition to these delicate cilia and zones of cilia, thicker hairs and stiff bristles, and more or less bent hooks, which are em- ployed in locomotion and for attachment. Certain fixed Infusoria as Stentor (fig. 138) and Cothumia secrete external coverings or shells, into which they retract themselves. Nourishment is taken in in a few cases by endosmosis through the whole surface of the body, , the parasitic Opalina. The Acineta feed themselves by sucking the body of their prey. They are without a mouth, and are incapable of taking in solid food. But they possess a number of long, narrow, contractile tentacles, which radiate from the surface of their bodies, and have the form of delicate tubes, presenting a structureless external wall and a FIS. 138.—Stentor semi-fluid granular axis. The Acineta applies one or more of these organs to the body of an extraneous organism, when the substance of the latter travels down the interior tentacle into the body of the Acineta (fig. 139). By far the greatest num- ber of Infusoria possess an oral aperture, usually near the anterior pole of the body, and a second aperture which acts as anus, and which can be seen in a definite part of the body as a slit during the exit of the excreta. The body parenchyma, which is bounded by the external membrane, is divided into a viscid exoplasni and a more fluid endoplasm, into gullet; P I', pulsating vacuole; N, nucleus. of the granular axis of the
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