Animal magnetism. See Magnetism and Mesmerism. -- Animal electricity, the electricity developed in some animals, as the electric eel, torpedo, etc. -- Animal flower (Zoöl.), 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. 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, Chætognatha, 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.

Cœlenterata, 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.