Page:The American Cyclopædia (1879) Volume XIV.djvu/756

 730 SEAL where it grows wild cook the leaf stalks and midribs of the leaves, after peeling them ; but when cultivated it is so managed that the buds as they push shall be blanched, and the edible portion is the tender, undeveloped leaves. The plant is raised from seeds, the seedlings re- maining a year in the seed bed, or from cut- tings, 2 to 4 in. long, of the roots of old plants, started in spring on a hotbed. Either year-old seedlings or plants from cuttings are set out in well enriched soil, 2 ft. apart, and the rows 3 ft. distant. On the approach of winter the plants are covered with 8 or 10 in. of sand or leaf mould, so that the shoots in forcing their way up through this in spring will bo blanched and tender ; when the tip of the shoot reaches the surface the blanching material is drawn away and the shoot cut at its junction with the Be* Kale (Crambe marttlma). Blanched Young Shoots. root. In England, one method of blanching is to use pots or cylinders of earthenware, tall- er in proportion than flower pots, or wooden boxes. By surrounding the pots with ferment- ing manure the plant may be forced. SEAL (Ang. Sax. */), an aquatic carnivorous mammal, the type of the family phocidce, con- stituting the old genus phoca (Linn.), which has been variously subdivided. The group of seals is at once distinguishable from other mam- mals by the structure and arrangement of the limbs ; the toes of all the feet are included al- most to the end in a common integument, con- verting them into broad fins, the bones being to a great extent within the skin of the trunk, and the tips armed with strong non-retractile claws ; the hind feet are thrown out backward, nearly horizontally, the very short tail being between them, and are the principal agents in swimming and diving; the fore paws when swimming are applied close to the body, and are used only in turning about. The body is cylindrical, tapering gradually backward ; the head is small and rounded, and the neck short ; the skin has an under woolly down, over which is a covering of long, smooth, and shining hairs, shedding water by an oily secretion, and offer- ing no resistance in swimming; between the skin and muscles is a layer of fat, as in ceta- ceans, giving that plumpness to the body ex- pressed in the common saying " as fat as a seal." The skull is thin, which renders the head light in the water, in the smaller species without the crests for muscular origins usually seen in carnivora ; the face short and broad ; zygomatic arches perfect and strong ; anterior nasal opening not terminal, and in some di- rected almost vertically for facilitating respira- tion when the animal comes to the surface ; the tentorium separating the cerebrum and cerebellum is formed wholly from the occi- pital bone; the orbits are continuous with the temporal fossffl, and the skull is very nar- row between them, the cranial cavity seeming like a box shut off from the facial portion of the head ; the lower part of the occipital bone is broad and thin, with an oval opening in the young in front of the great foramen covered with membrane, but closed by bone in the adults, and the condyles are much larger than in other carnivora ; the inf raorbital foramina are very large, for the exit of the branch of the fifth pair of nerves, which supplies the sen- sitive whiskers ; the nasal bones are very short. The incisor teeth are small and pointed, the canines not generally very projecting, but much worn, and the molars with laterally com- pressed crowns, sharp cutting edges, many- pointed, and usually single-rooted ; the number varies in the different genera. The cervical vertebras are short, the dorsals and pairs of ribs 15, and the lumbar 5 (in the common seal), the caudals very imperfectly developed, the ante- rior portion of the sternum prolonged far up the neck and movable, the scapula small with a moderate and nearly central spine, and the coracoid and clavicles absent; the bones of the forearm short, wide, and flattened ; the fe- mur at a right angle with the spine and the leg, very short and comparatively immovable, giv- ing greater freedom of motion to the rest of the limb ; tibia and fibula long and flat, the for- mer with a double curvature ; metatarsal bonea and toes long and slender, and the foot wide and paddle-like. The mouth has thick fleshy lips, with many long, knotted, and exceedingly sensitive bristly whiskers with nerves from the fifth pair ; the tongue rough and bifurcated at the end ; nostrils capable of being completely closed under water; external ears in most merely small valves which close the auditory opening; the eyes (with nictitating membrane) large, full, bright, and expressive of great in- telligence ; brain large, and with many convo- lutions ; mammas two or four, ventral, near the umbilicus, enclosed in folds of the skin ; the intestinal canal is very long for a carnivorous animal ; the posterior vena cava, close to the liver, has a large sac or sinus which receives five hepatic veins, serving to retain a portion of the blood from the heart while the animal ia under water ; the foramen male in the heart and the ductus arteriosu* are often found per- vious ; the stomach is elongated, and has a vil-