Volume 1

A student's text-book of zoology / by Adam Sedgwick.

  • Sedgwick, Adam, 1854-1913.
Date:
1898-1909
Catalogue details

Licence: In copyright

Credit: A student's text-book of zoology / by Adam Sedgwick. Source: Wellcome Collection.

    67/640 (page 51)
    Scyphidia Lachniaim, ectopar.; Gerda Clap, and L., f. w.; Ashjlozoon Engelmann, f.w.; Vorticella L., 'with long contractile fibre for attachment, f.'W. and m.; Carchcsium Ehrb., colonial, f.w.; Zoothamniimi Ehrb., colonial, f.w. and m.; Qlossatella Biitschli, attached, but without stalk; Epistylis Ehrb., colonial, and lihahdostyla Kent, solitary, stalk without contractile fibre ; Opcrcularia Goldf.; Ophrydiuvn. Bory ; Cothurnia Ehrb.; Eaginicola Lam.; Lagenophrys Stein, with lorica. Forms of uncertain position : MuUicilia Cienk., covered by long flagella-like cilia, m. and f.w.; Grassia Fisch, covered with long cilia, parasitic in stomach of frog and in blood of Hyla viridis; Magosphoera Haeckel, free-swimming ciliated forms occurring in spherical colonies. Sub-class III. ACINETAEIA. Infusoria with linohhed tejitacle-lihe p>rocesses which serve as sueltimj tubes. Ciliated in the young state. Tliese animals are always sedentary in habit, and either free or attached; when the latter they may be sessile or stalked. They prey upon the living tissues of other organisms by means of their tentacles. The latter are processes of the cor- tical protoplasm, and are of two main kinds, con- ixecting which there are intermediate forms : (1) the so-called prehensile tenta- cles which taper distally, although they do not end in a sharp jxoint, and (2) the suctonaf which are cylindrical in shape and rounded at the end which ferrumequinum Ehrb., sucking the body of a small infusorian(E?ic/!eiys), after Lachmann. may even be swollen into r suctorial tentacle; r vacuole ; nucleus. a distinct knob. The tentacles of both kinds appear to contain a canal which opens distally to the exterior, and leads at the other end into the central protoplasm of the body. The fluid or semi-fluid contents of their prey pass down these canals in a current, the cause of which is not quite understood. IVIaupas has suggested that the transparent ecto- ])lasm of the Acinetan first passes in an invisible current by the tentacle into the body of the prey, there absorbs the protoplasm, and then returns with its burden to its own body in a current which can be traced by the granule contents of the ^^I’otoplasm. All tentacles cU/.