SOLIPEDA. Syn. Solidungula, Pachy dernzes Solipedes. — An important group of herbivorous quadrupeds, regarded by Cuvier as constituting a third family of his order Pachydermata, and defined as " animaux sabots non ruminans," or non-ruminant, un gulate quadrupeds. They form, however, a race of animals that presents many remark able peculiarities of structure, and, from their great importance to mankind, demand, in a work like the present, a somewhat minute description of their anatomy and general or ganisation.
The Solipeda, zoologically considered, com prehend but the single genus EQUUS, at once distinguishable from all other quadrupeds by the remarkable construction of the anterior and posterior extremities, each of tbe four feet appearing externally to consist of but a single toe enclosed in a solid hoof of horn, although, within, there are found con cealed beneath the skin the rudiments of two other digits, appended to each side of the metacarpal and metatarsal portion of the limb.
The genus EQUUS is further characterised by the following peculiar disposition of the dental apparatus : — There are six sharp and trenchant incisors both in the upper and in the lower jaw, and an equal number of grind ing teeth, the crowns of which are of a square form, each having its surface intersected by deep plates of enamel, arranged in the shape of four crescentic masses, in addition to which there exists in the teeth of the upper jaw a small disc of enamel, situated upon the inner border of each tooth.
The males have, moreover, two small canine teeth developed in the upper jaw, and some times in the lower one also ; but these canine teeth, or lushes (tusks), as they are generally called, are for the most part altogether want ing in the females. A considerable interspace exists between the canine teeth and the first molar, so that that portion of the mouth of the horse which is opposite to the commis sure of the lips is devoid of any dental arma ture, a circumstance of which man has availed himself for the purpose of introducing into the mouth of these animals that bit by the aid of which he is enabled to subjugate his steed, and thus secure to himself the services of an assistant not less conspicuous for his indomitable strength than for his matchless docility. The stomach of the Solipeds is
simple in its form, and of moderate dimen sions, but their intestinal canal is of very great length, and the ccecum and colon enor mous in their proportionate size.
Thus characterised, the genus Equus is found to comprehend several different races of quadrupeds that are generally regarded by modern naturalists as constituting so many distinct species. These are — 1st. The Horse (Equus Caballus), " man's noble companion in the chase or on the battle-field, in the labours of agriculture, in the arts, or in commerce." The original country whence the horse has been disseminated through the whole world has now become a matter of uncertainty, although most probably the wide plains of eastern Europe and of' Asia, where wild horses still abound, may be pointed out as their central station. That they were in com mon use in Egypt from the very earliest pe riod of which we have any record, is evident from the sacred writings (vide Gen. c. xlvii. v. 17., and c. 1. v.9.), and hence it is supposed to have been derived by the Arabs, Persians, Ethiopians, Indians, Parthians, Scythians, &c.
At the present day, -wild horses are by ncr means common even in their native regions, owing to the encroachments of man upon their original haunts; but, on the other hand, they have spread over the vast prairies of the new continent, and may now be said to be as extensively distributed as the human race itself.
The second species admitted by zoologists to form a distinct race is the Dzigguetai (E'quus Hemionus), intermediate in size be tween the horse and the ass, from both of vvhich it is distinguished by its colour, which is light bay, with a black mane and dorsal line, and it also has a black tuft of hair at the end of its tail. This animal is found in large troops among the sandy plains of Cen tral Asia.