The Carnivora with the Bears, Apes, and Man, as being the proper representatives of the senses, conclude or wind up the list. They alone have a regular dental formula. We have thus—
I. Splanchno-Thricozoa; Mice, Edentata, Marsupialia, Shrews and Bats.
II. Sarco-Thricozoa; Whales, Pachyderms, Ruminants.
III. Æsthesio-Thricozoa; Carnivora, Seals, Bears, Apes and Man.
3563. It is here shown, just as distinctly as in the series of the classes, that no simple scale exists in the history of development, and consequently in the arrangement of animals. The Mouse-like species stand off from the rest, and then follow the entirely different Ungulata with the Pigs and Ruminants, which once again diverge in like manner, and make room for the development of the Seals, which then proceed through the Dogs, &c., in a less interrupted series up to Man.
He who marvels at this, let him take and set the table of the class-series before his eyes, and he must give utterance with us to the following words; namely, that the lower animals diverge or turn aside, and the entirely different Fishes, Reptiles, and Birds follow, which, once again diverging, make room for the development of the Thricozoa, or, in other words, the "Compendium Animalium." A perfect parallelism is thus found to exist between the classes of animals generally and the families of Thricozoa; but no linear or continuously progressive connexion is discoverable between one set and the other, but an appearance by fits or starts of new forms, just as the systems and organs also are not gradually evolved metamorphoses of one system, but sudden productions "en avant" with new tissues, forms, and functions. The animal system is a multifariously-constructed temple, with its nave, choir, chapels, and towers, while these again are present with the whole diversity of forms, which belongs to them in their several characters or bearings.
A. SPLANCHNO-THRICOZOA—PFOTENTHIERE, MAUSARTIGE.
3564. Small animals with irregular set of teeth; four feet with claws. The regular set of teeth has included all kinds of teeth, and with them four or six incisors.
A set of teeth is irregular, which has more or less than the ordinary number of incisors, in which moreover one or the other kind of tooth is wanting, or if it is separated by a breach or interspace.
The small Thricozoa divide into three orders.
The one have blunt uniform molars, two rodent or gnawing-teeth, and no canines—Rodentia.
The others have, one might say, a wholly aberrant and confused dental formula, there being at one time too few, at another too many teeth; molars uniform, with perfectly irregular incisors and canines—Sloths, Marsupials.