Outlines of zoology . among which are such familiar forms as the commonEuglena of ponds ; the Monads; Volvox, a colonial form ; Codosiga, acolony in which the individual cells are furnished with a collar (Choano-flagellata). The HEemoflagellata are important blood parasites, generallycalled Trypanosomes (see p. 121), SYSTEMATIC SURVEY. lU Modified flagellate lorms are included in the groups Dinoflagellataand Cystoflagellata, in both of which there are two flagella, differ-ently placed in the two cases. In the first are included Peridinium andCeratium; in the latter, the large phosphorescent No
Outlines of zoology . among which are such familiar forms as the commonEuglena of ponds ; the Monads; Volvox, a colonial form ; Codosiga, acolony in which the individual cells are furnished with a collar (Choano-flagellata). The HEemoflagellata are important blood parasites, generallycalled Trypanosomes (see p. 121), SYSTEMATIC SURVEY. lU Modified flagellate lorms are included in the groups Dinoflagellataand Cystoflagellata, in both of which there are two flagella, differ-ently placed in the two cases. In the first are included Peridinium andCeratium; in the latter, the large phosphorescent Noctiluca. Theyform an important part of the plankton of lakes and sea. As (9) Ciliata are included a very large number of forms, more orless closely resembling Parammcium or Vorticella, and very abundantin infusions; some, such as Opalina, in the intestine of the frog, areparasitic. As specially modified Ciliata are included (10) Acinetaria, highlyspecialised forms, ciliated when young, but usually furnished when adult. Fig. 52.—Optical section of a Radiolarian [Actinomma).—After Haeckel. Ut Nucleus; ^, wall of central capsule; c, siliceous shell withinnucleus ; c\ middle shell within central capsule ; c^, outer shellin extra-capsular substance. Four radial spicules hold thethree spherical shells together. with suctorial tentacles. They are fixed in adult life, and feed on otherProtozoa. As examples may be given Acineta ; Dendrosoma, formingbranched colonies; and Ophryodendron, without suctorial , like Spharophrya, are minute and parasitic. D. Predominantly encysted Protozoa, —Sporozoa. —Formslike Gregarina and Monocystis are included in a group of the (11)Sporozoa, the Gregarinida in the strict sense. They are parasites inthe gut or body cavity of many Invertebrates, especially is a type of the Coccidiidea, which are intracellular parasites-occurring in Arthropods, Molluscs, and Vertebrates. A very im-portant group, with a life cycle e
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Keywords: ., bookcentury1900, bookdecade1910, bookidcu3192, booksubjectzoology
