CLASSIFICATION OF ANIMALS. 821 CLASSIFICATION OF ANIMALS. Branch 1. Animalia Vertcbrata. Classes: (1) ^liimmalia. (2) Aves. (3) Keptilia. (4) Pisces. Branch 2. Animalia Volliisia. Classes: (1) Cephalopoda (not subdivided). (2) Pteropoda (not subdivided). (3) Gastroi)oda. (Orders: Pulnionata, Xudibranehia, Inferobranchia, Tecti- branchia, Ilcteropoda, Peetinibraiichia, Tubuli- luanchia, Scutibranohia, Cvclobranclua.) (4) Aicpbala. (Orders: Testacca, Tunieata.) (5) iJraohiopoda (no subdivisions), (d) Cirrhopoda. Branch 3. Animalia ArticuUtta. Classes: (1) Annelilcs. (Orders: Tubieola;, Dorsibranch- iie. Abrancliia;. ) (2) Crustacea. (Section 1: Jilalacostraca. Orders: Deoapoda. Stomatopoda, Ampliijjoda, La-modipoda, Isopoda. Section 2: Entouiostraca. Orders: Brachiopoda, Poscilo- poda, Trilobita;.) (3) Arachnides. (Orders: Pulmonari;v, Trachearise.) (4) Insects. {Orders: ilyriapoda. Thysanura, Parasita, Suctoria. C'o- leoptera. Ortlioptera. Heniiptera, Xeuroptera, Hynienoptera, Ithipiptera. Diptera. ) Branch 4. Animalia Hadiata. Classes: (1) Echinodernis. (Orders: Pedicellata, Apoda.) (2) Intestinal Worms. (Orders: Xematoidea, Parenchyma tosa.) (3) Acalephse. (Orders: }>implices. Hydrostatieie.) (4) Polypi (Aiitho- 2oa, Hydroida. Bryozoa, CoraIlina>, Spongia>). 'Orders: Carnosi, Gelatinosi, Polypiarii.) (5) Infusoria. (Orders: Rotifera, Homogenea.) Lamarck to Leuckart.- — Probably to Lamarck, more than to any other systematist, we are in- debted for the term Invertebrata and to the ar- rangement of groups in an ascending series. In his Uistoire naturcUe dcs animaux sans vcrtc- brcs (Paris. ISOl), he classifies the invertebrates as follows (accepting the vertebrates as arranged by Cuvier) : I. Apathetic Animals. Do not feel; no brain, 110 senses: rarely articulated. Class 1. Infusoria. Orders: Kuda, Appendi- culata. Class 2. Polypi. Orders: Ciliata (Rotifera). Denudati (hydroids), Vaginati (Anthozoa and Bryozoa), and Xatant«s (crinoids and some halcyonoids ) . Class 3. Radiaria. Orders: JloUia (Acale- pha'). echinoderms (including HolothuriiB and Actinia-) . Class 4. Tunieata. Orders: Botryllaria (com- pound ascidians), Ascidia (simple ascidians). Class 5. Vermes. Orders: Molles and Rigi- duli (intestinal worms and gordius), Hispiduli (Xais), EpizoariiP (epizoa and lerna;ans). II. Sensitive Animals. Class 6. Insects (hexapods). Orders: Aptera, Diptera, Hemiptera. Lepidoptera, Hynienoptera, Xeuroptera, Orthoptera, Coleojjtera. Class 7. Araclinids. Orders: Antennatotra- cheales (Thysanura and Myriapoda), Exantenna- totracheales and Exantennatobrancheales (Arach- nida proper). Class 8. Crustacea. Orders: Heterobranchia (Brancliiopoda. Isopoda. Amphipoda, Stoma- poda) and Iloniobranchia (Decapoda). Class n. Annelids. Orders: Apoda, Antennata, Sedentaria. Class 10. Cirripeds. Orders: Sessilia and Peduneulata. Class 11. Conchifera. Orders: Dimyaria, Mon- omyaria. Class 12. ^[ollusks. Orders: Pteropoda. Gas- tropoda, Traehelipoda. Cephalopoda. Heteropoda. Siebold and Stannius (IS45) also divided the animal kingdom into vertebrates and in- vertebrates : and among the invertebrates the Protozoa were recognized as a sep:iratc type, and Vermes came to have verj' much the signifi- cance that it lias in our modern classifications. The classification of Leuckart is interesting, liceause it comes near to our present conceptions of the relationship of animals, and because of the fact that its autlior was a great teacher of zoology: and, lience, liis classification has had great inlluence in education. Leuckart, Die Moii>lioloyie iind die Vcruandt.schaftsverhiillnisse dcr irirlcllosen Thierc (Brunswick, 1S48) . divides animals above Protozoa (to which he paid no at- tention) into six 'types,' as follows: Type I. Cnlenterata. Class 1. Polypi. (Orders: Anthozoa and Cyli- cozoa.) Class 2. Acalephcc. (Orders: Discophora; and Ctenophora ) Type II. Echinodermata. Class 3. Pelmatozoa. (Orders: Cystidea and Crinoidea.) Class 4. Actinozoa. (Orders: Echinida and Asterida.) Class 5. Seytodermata. (Orders: HolothuriiB and Sipunculida.) Type III. Vermes. Class G. Anenterati. (Orders: Cestodes and Acanthocephali.) Class 7. Apodes. (Orders: Kemertini, Tur- bellarii, Trenuitodes, and Hirudinei.) Class S. Ciliati. (Orders: Bryozoa and Roti- feri.) Class 9. Annelides. (Orders: Xematodes, Lum- bricini, and Branchiati.) Type IV. Arihropoda. Class 10. Crustacea. (Orders: Entomostraca and Jlalacostraca. ) Class 11. Inspcta. (Orders: Jlyriapoda, .raclinida, and Hexapoda.) Type V. iloUusea. Class 12. Tunieata. (Orders: Ascidiae and Salpse.) Class 13. Acephala. (Orders: Lamellibranchi- ata and Brachiopoda.) Class 14. Gastropoda. (Orders: Heterobran- chiata. Dermatobranchia, Heteropoda, Cteno- braiichia, Pulnionata, and Cyclobranchia.) Class 15. Cephalopoda. Type VI. Vertebrata (according to Cuvier). Oken, Von Baer, and Agassiz. — The foregoing
- ind certain other classifications had been devel-
oped in England, France, and Germany, under the guidance of anatomy ; but, in many of them, the idea of the complexity of structure of ani- mals seemed to outweigh the idea of unity of structure. During the early part of tlie nine- teenth century another school developed in Ger- many, under the leadership of Schelling — the Sdiool of Xatural Philosophy — which has ex- tended its infiuence to all the physical sciences. Of its doctrines such men as Geofi'roy Saint llilaire in France, and Goethe and Oken in Ger- many, became expounders, and taught that unity prevailed everywhere; hence, the animal kingdom was composed of an unbroken series of animals. The most important system of classification evolved by tliis school is that of Oken. Cor- responding with the invertebrates is Oken's in- testinal-body, or touch-animals, as he called them {Lchrbuch dcrKatitrphilusophie, Jena, 1810).
