What is "infusoria"

Infusoria \In`fu*so"ri*a\, n. pl. [NL.; -- so called because found in infusions which are left exposed to the air for a time. See Infuse.] (Zo["o]l.) One of the classes of Protozoa, including a large number of species, all of minute size. Formerly, the term was applied to any microbe found in infusions of decaying organic material, but the term is now applied more specifically to one of the classes of the phylum Ciliophora, of ciliated protozoans.

Note: (From 1913 dictionary): They are found in all seas, lakes, ponds, and streams, as well as in infusions of organic matter exposed to the air. They are distinguished by having vibrating lashes or cilia, with which they obtain their food and swim about. They are devided into the orders Flagellata, Ciliata, and Tentaculifera. See these words in the Vocabulary. Formely the term Infusoria was applied to all microscopic organisms found in water, including many minute plants, belonging to the diatoms, as well as minute animals belonging to various classes, as the Rotifera, which are worms; and the Rhizopoda, which constitute a distinct class of Protozoa. Fossil Infusoria are mostly the siliceous shells of diatoms; sometimes they are siliceous skeletons of Radiolaria, or the calcareous shells of Foraminifera.

Animal \An"i*mal\, a. [Cf. F. animal.]

1. Of or relating to animals; as, animal functions.

2. Pertaining to the merely sentient part of a creature, as distinguished from the intellectual, rational, or spiritual part; as, the animal passions or appetites.

3. Consisting of the flesh of animals; as, animal food.

   Animal magnetism. See Magnetism and Mesmerism.

   Animal electricity, the electricity developed in some animals, as the electric eel, torpedo, etc.

   Animal flower (Zo["o]l.), a name given to certain marine animals resembling a flower, as any species of actinia or sea anemone, and other Anthozoa, hydroids, starfishes, etc.

   Animal heat (Physiol.), the heat generated in the body of a living animal, by means of which the animal is kept at nearly a uniform temperature.

   Animal spirits. See under Spirit.

   Animal kingdom, the whole class of beings endowed with animal life. It embraces several subkingdoms, and under these there are Classes, Orders, Families, Genera, Species, and sometimes intermediate groupings, all in regular subordination, but variously arranged by different writers.

   Note: The following are the grand divisions, or subkingdoms, and the principal classes under them, generally recognized at the present time: Vertebrata, including Mammalia or Mammals, Aves or Birds, Reptilia, Amphibia, Pisces or Fishes, Marsipobranchiata (Craniota); and Leptocardia (Acrania). Tunicata, including the Thaliacea, and Ascidioidea or Ascidians. Articulata or Annulosa, including Insecta, Myriapoda, Malacapoda, Arachnida, Pycnogonida, Merostomata, Crustacea (Arthropoda); and Annelida, Gehyrea (Anarthropoda). Helminthes or Vermes, including Rotifera, Ch[ae]tognatha, Nematoidea, Acanthocephala, Nemertina, Turbellaria, Trematoda, Cestoidea, Mesozea. Molluscoidea, including Brachiopoda and Bryozoa. Mollusca, including Cephalopoda, Gastropoda, Pteropoda, Scaphopoda, Lamellibranchiata or Acephala. Echinodermata, including Holothurioidea, Echinoidea, Asterioidea, Ophiuroidea, and Crinoidea. C[oe]lenterata, including Anthozoa or Polyps, Ctenophora, and Hydrozoa or Acalephs. Spongiozoa or Porifera, including the sponges. Protozoa, including Infusoria and Rhizopoda. For definitions, see these names in the Vocabulary.

n. 1 (en-irregular plural of: infusorium) 2 (context biology English) The many minute aquatic creatures, such as protozoa and unicellular algae found in fresh water habitats

Infusoria is a collective term for minute aquatic creatures such as ciliates, euglenoids, protozoa, unicellular algae and small invertebrates that exist in freshwater ponds. Some authors (e.g., Bütschli) used the term as a synonym for Ciliophora. In modern formal classifications, the term is considered obsolete; the microorganisms previously included in the Infusoria are mostly assigned to the kingdom Protista which itself is a polyphyletic assemblage of groups.