SKELETON OF THE SHEEP AS COVERED BY THE MUSCLES.
1. The intermaxillary bone. 2. The nasal bones. 3. The upper jaw. 4. The union of the nasal and upper jaw-bones. 5. The union of the molar and lachrymal bones. 6. The orbits of the eye. 7. The frontal bone. 8. The lower jaw. 9. The incisor teeth, or nippers. 10. The molars or grinders. 11. The ligament of the neck supporting the head. 12. The seven vertebræ, or the bones of the neck. 13. The thirteen vertebræ, or bones of the back. 14. The six vertebræ of the loins. 15. The sacral bone.[58] 16. The bones of the tail, varying in different breeds from twelve to twenty-one. 17. The haunch and pelvis. 18. The eight true ribs, with their cartilages. 19. The five false ribs, or those that are not attached to the breast-bone. 20. The breast-bone. 21. The scapula, or shoulder-blade. 22. The humerus, bone of the arm, or lower part of the shoulder. 23. The radius, or bone of the fore-arm. 24. The ulna or elbow. 25. The knee with its different bones. 26. The metacarpal or shank-bones—the larger bones of the leg. 27. A rudiment of the smaller metacarpal. 28. One of the sessamoid bones. 29. The first two bones of the foot—the pasterns. 30. The proper bones of the foot. 31. The thigh-bone. 32. The stifle-joint and its bone—the patella. 33. The tibia, or bone of the upper part of the leg. 34. The point of the hock. 35. The other bones of the hock. 36. The metatarsal bones, or bone of the hind-leg. 37. Rudiment of the small metatarsal. 38. A sessamoid bone. 39. The first two bones of the foot—the pasterns. 40. The proper bones of the foot.
Division. Vertebrata—possessing a back-bone.
Class. Mammalia—such as give suck.
Order. Ruminantia—chewing the cud.
Family. Capridæ—the goat kind.
Genus. Oris—the sheep family.
Of this Genus there are three varieties:
Oris, Ammon, or Argali.
Oris Musmon.
Oris Aries, or Domestic Sheep.
Of the latter—with which alone this treatise is concerned—there are about forty well known varieties. Between the oris, or sheep, and the capra, or goat, another genus of the same family, the distinctions are well marked, although considerable resemblance exists between them. The horns of the sheep have a spiral direction, while those of the goat have a direction upward and backward; the sheep, except in a single wild variety, has no beard, while the goat is bearded; the goat, in his highest state of improvement, when he is made to produce wool of a fineness unequalled by the sheep—as in the Cashmere breed—is mainly, and always, externally covered with hair, while the hair on the sheep may, by domestication, be reduced to a few coarse hairs, or got rid of altogether; and, finally, the pelt or skin of the goat has thickness very far exceeding that of the sheep.
The age of sheep is usually reckoned, not from the time that they are dropped, but from the first shearing; although the first year may thus include fifteen or sixteen months, and sometimes more. When doubt exists relative to the age, recourse is had to the teeth, since there is more uncertainty about the horn in this animal than in cattle; ewes that have been early bred, appearing always, according to the rings on the horn, a year older than others that have been longer kept from the ram.
FORMATION OF THE TEETH.
Sheep have no teeth in the upper jaw, but the bars or ridges of the palate thicken as they approach the forepart of the mouth; there also the dense, fibrous, elastic matter, of which they are constituted, becomes condensed, and forms a cushion or bed, which covers the converse extremity of the upper jaw, and occupies the place of the upper incisor, or cutting teeth, and partially discharge their functions. The herbage is firmly held between the front teeth in the lower jaw and this pad, and thus partly bitten and partly torn asunder. Of this, the rolling motion of the head is sufficient proof.
The teeth are the same in number as in the mouth of the ox. There are eight incisors or cutting-teeth in the forepart of the lower jaw, and six molars in each jaw above and below, and on either side. The incisors are more admirably formed for grazing than in the ox. The sheep lives closer, and is destined to follow the ox, and gather nourishment where that animal would be unable to crop a single blade. This close life not only loosens the roots of the grass, and disposes them to spread, but by cutting off the short suckers and sproutings—a wise provision of nature—causes the plants to throw out fresh, and more numerous, and stronger ones, and thus is instrumental in improving and increasing the value of the crop. Nothing will more expeditiously and more effectually make a thick, permanent pasture than its being occasionally and closely eaten down by sheep.
In order to enable the sheep to bite this close, the upper lip is deeply divided, and free from hair about the centre of it. The part of the tooth above the gum is not only, as in other animals, covered with enamel, to enable it to bear and to preserve a sharpened edge, but the enamel on the upper part rises from the bone of the tooth nearly a quarter of an inch, and presenting a convex surface outward, and a concave within, forms a little scoop or gorge of wonderful execution.