The group of Primæval animals (Protozoa) within the compass which we here assign to this tribe, comprises the most ancient and the simplest primary forms of the animal kingdom; for example, the five oldest phyletic stages of development previously mentioned, and besides these the Infusoria and Gregarinæ, as well as all those imperfect animal forms, for which, on account of their simple and indifferent organization, no place can be found in any of the other six animal tribes. Most zoologists, in addition to these, Include among the Protozoa a larger or smaller portion of those lowest organisms, which we mentioned in our neutral kingdom of Protista (in Chapter XVI.). But these Protista, especially the large division of the Rhizopoda, which are so rich in forms, cannot be considered as real animals for reasons previously given. Hence, if we here leave them out of the question, we may accept two main classes or provinces of real Protozoa, namely, Egg animals (Ovularia) and Germ animals (Blastularia). To the former belong the three classes of Archezoa, Gregarinæ, and Infusoria, to the latter the two classes of Planæads and Gastræads.
| SYSTEMATIC SURVEY | |||||||
| Of the 16 Main Classes and 38 Classes of the Animal Kingdom. | |||||||
| Tribes or Phyla of the Animal Kingdom. | Main Classes, Branches or Clades of the Animal Kingdom. | Classes of the Animal Kingdom. | Systematic Name of the Classes. | ||||
| A. Primæval Animals Protozoa |
| I. Egg-animals Ovularia |
| 1. | Archaic animals | 1. | Archezoa |
| 2. | Gregarines | 2. | Gregarinæ | ||||
| 3. | Infusoria | 3. | Infusoria | ||||
| II. Mulberry animals Ovularia |
| 4. | Planæads | 4. | Planæadas | ||
| 5. | Gastræads | 5. | Gastræadas | ||||
| B. Animal Plants Zoophyta |
| III. Sponges Spongiæ |
| 6. | Sponges | 6. | Porifera |
| IV. Sea-nettles Acalephæ |
| 7. | Corals | 7. | Coralla | ||
| 8. | Hood-jellies | 8. | Hydromedusæ | ||||
| 9. | Comb-jellies | 9. | Ctenophora | ||||
| C. Worms Vermes |
| V. Bloodless worms Acœlomi |
| 10. | Planary worms | 10. | Platyhelminthes |
| V. Bloodless worms Acœlomi |
| 11. | Round worms | 11. | Nemathelminthes | ||
| 12. | Moss-polyps | 13. | Bryozoa | ||||
| 13. | Sac-worms | 13. | Tunicata | ||||
| 14. | Proboscideans | 14. | Rhynchocœla | ||||
| 15. | Star-worms | 15. | Gephyrea | ||||
| 16. | Wheel animalcules | 16. | Rotatoria | ||||
| 17. | Ring-worms | 17. | Annelida | ||||
| D. Molluscs Mollusca |
| VII. Headless shellfish Acephala |
| 18. | Lamp-shells | 18. | Spirobranchia |
| 19. | Mussels | 19. | Lamellibranchia | ||||
| VIII. Head-bearing Eucephala |
| 20. | Snails | 20. | Cochlides | ||
| 21. | Cuttles | 21. | Cephalopoda | ||||
| E. Star-fishes Echinoderma |
| IX. Ringed-arms Colobrachia |
| 22. | Sea-stars | 22. | Asterida |
| 23. | Lily-stars | 23. | Crinoida | ||||
| X. Armless Lipobrachia |
| 24. | Sea-urchins | 24. | Echinida | ||
| 25. | Sea-cucumbers | 25. | Holothuriæ | ||||
| F. Articulated Animals Arthropoda |
| XI. Gill-breathers Carides |
| 26. | Crab-fish | 26. | Crustacea |
| X. Armless Lipobrachia |
| 27. | Spiders | 27. | Arachnida | ||
| 28. | Centipedes | 28. | Myriopoda | ||||
| 29. | Flies | 29. | Insecta | ||||
| G. Vertebrate Animals Vertebrata |
| XIII. Skull-less Acrania |
| 30. | Lancelets | 30. | Leptocardia |
| XIV. Single-nostriled Lipobrachia |
| 31. | Lampreys | 31. | Cyclostoma | ||
| XV. Amnion-less Anamnia |
| 32. | Fishes | 32. | Pisces | ||
| 33. | Mud-fish | 33. | Dipneusta | ||||
| 34. | Sea dragons | 34. | Halisauria | ||||
| 35. | Amphibians | 35. | Amphibia | ||||
| XVI. Amnion-bearing Amniota |
| 36. | Reptiles | 36. | Reptilia | ||
| 37. | Birds | 37. | Aves | ||||
| 38. | Mammals | 38. | Mammalia | ||||
MONOPHYLETIC PEDIGREE OF ANIMALS
| Vertebrata (Vertebrated animals) Craniota | ||||||||
| Arthropoda (Articulated Animals) Tracheata | │ │ │ │ | Mollusca (Molluscs) Eucephala | ||||||
| Echinoderma (Star-fishes) | │ │ | │ │ | │ │ | |||||
| Lipobrachia | Crustacea | Acrania | │ | |||||
| │ | Annelida | │ | │ | Tunicata | Acephala | |||
| Colobrachia │ | │ │ | │ │ | │ │ | │ │ | Bryozoa │ | │ │ | ||
| │ | Gephyrea | │ | │ | Rotatoria |
|
| ||
| │ | │ | │ | │ | │ | │ | │ | ||
|
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| Vermes (Worms) | │ │ | |||||||
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| │ | ||||||||
| Cœlomati (Worms with a body-cavity) | ||||||||
| │ | Platyhelminthes | |||||||
| │ | │ | |||||||
| Zoophyta (Animal Plants) |
(Worms without body-cavity) | |||||||
| Spongiæ | Acalephæ | │ | ||||||
| │ | │ | │ | ||||||
| │ | |||||||
| Protascus | Prothelmis | |||||||
| │ | │ | |||||||
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| │ | ||||||||
| │ │ │ | Protozoa (Primæval animals) | |||||||
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| Gastræa | ||||||||
| │ | Infusoria | |||||||
| Planæa | │ | Gregarinæ | ||||||
| │ | │ | │ | ||||||
| Synamœbæ |
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| │ | │ | |||||||
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| │ | ||||||||
| Amœbæ | ||||||||
| │ | ||||||||
| Monera | ||||||||
The first province of the Protozoa consists of the Egg animals (Ovularia); we include among them all single-celled animals, all animals whose body, in the fully developed state, possesses the form-value of a simple plastid (of a cytod or a cell), also those simple animal forms whose body consists of an aggregation of several cells perfectly similar one to another.
The Archaic animals (Archezoa) form the first class in the series of Egg animals. It contains only the most simple and most ancient primary forms of the animal kingdom, whose former existence we have proved by means of the fundamental law of biogenesis; they are, (1) Animal Monera; (2) Animal Amœbæ; (3) Animal Synamœbæ. We may, if we choose, include among them a portion of the still living Monera and Amœbæ, but another portion (according to the discussion in Chapter XVI.) must on account of their neutral nature be considered as Protista, and a third portion, on account of their vegetable nature, must be considered as plants.