summer months. Its length varies from 12 to 18 inches; the color of the upper parts is greenish brown with a black spot on the shoulder, the belly silvery, and the whole surface iridescent. The flesh is not highly esteemed as food and is very full of small bones; but it is rich in oil and nitrogen.
Economic Uses. The menhaden is one of the most interesting and valuable of American seafishes, and its catching and utilization give occupation to a large amount of capital and number of men and vessels. (See Fisheries.) It is extremely irregular in its movements and numbers, migrating into deep water or to warm latitudes on the approach of cold weather, and reappearing north of Cape Hatteras with advancing warm weather. In some years it has been extremely numerous as far north as Nova Scotia; while there have been periods when the fish seemed to have forsaken America altogether. It appears along shore in schools, which may contain a million or two of fishes, swimming near the surface. With ordinary care such a school may be surrounded by a net, operated from two row-boats, and then hauled to the ship's side, where the net is pursed and the fish are dipped out and thrown into the hold. A catch of half a million is not unusual. Formerly small sailing vessels were altogether used, but since abmit 1875 high-powered, tug-like steamers have mostly replaced them. All along the shore from the Carolinas to eastern Maine are ‘factories’ where these loads of menhaden are sold. Their bodies yield oil of a superior sort, useful for every purpose to which any fish or whale oil may be applied. This is obtained by boiling and pressing. (See Oil.) From the residue is made a nutritious animal food called ‘fish meal,’ and a highly nitrogenous ingredient of artificial guanos. In early times, following the example of the Indians, the fish themselves used to lie spread upon the farms near shore, and plowed into the soil; but it was found that apart from the extremely disagreeable taint this gave to the air of the whole region, the soil was injured by saturation with oil.
|
| FISH-LOUSE OF THE MENHADEN. |
| A degraded entomostracan parasite (Lerneonema radiata); the ‘rooted’ head is at the right. |
Great quantities of menhaden are also used as bait in the Banks fisheries; are sold fresh in the markets, very cheaply; and are salted for domestic use or to be exported to the West Indies; and the young are extensively canned in oil as ‘American sardines’ and ‘shadines.’ The fish has, however, a still higher economic value in serving as the food of other fishes important to us. It itself subsists mainly upon minute vegetable material contained in the mud of bays and soft shores, and is enormously fecund. Every predaceous animal in the sea eats menhaden. Goode estimated that the total number of menhaden devoured by fishes annually could only be counted by millions of millions; and he declared that were the menhaden to disappear three-fourths of the value of the American fisheries would instantly vanish.
The menhaden is known by an extraordinary number of different names: as ‘pogy,’ in Maine; ‘bony fish’ in eastern Connecticut; ‘white fish’ in western Long Island Sound; ‘bunker,’ a shortening of ‘mossbunker’ (q.v.), about New York and New Jersey; ‘bugfish’ or ‘bughead’ in Delaware and Chesapeake bays, referring to a parasitic crustacean (see Parasite, Animal) in the mouths of the southern menhaden; and farther south as ‘fatback,’ ‘yellowtail,’ and ‘savega’—the last the Portuguese term in South America. The menhaden of the Gulf of Mexico is a variety locally called ‘alewife,’ ‘herring,’ etc.; and other varieties extend the range of the species to Brazil.
Bibliography. Goode, “The Menhaden,” an elaborate memoir, in Report of the United States Fish Commission, part v. (Washington, 1877); and a more condensed account in Fishing Industries, sec. i. (Washington, 1884). For a picturesque account of catching menhaden, see “Around the Peconics,” in Harper's Magazine, vol. lvii. (New York, 1881). See Plate of Herring and Shad.
MENIN, me-năN′. A frontier town of West Flanders, Belgium, situated 30 miles southwest of Ghent, on the left bank of the Lys, which here forms the French boundary (Map: Belgium, B 4) . It has a handsome church, a seminary, manufactures of lace and cotton textiles, and a famous old brewery. It was formerly fortified, but its works have been demolished. Population, in 1890, 13,700; in 1900, 19,312.
MEN′INGI′TIS. An inflammation of the meninges, the membranes covering the brain and spinal cord. These are three in number: the pia mater, lying in contact with the substance of the brain and cord; the dura mater, lining the cranial cavity and spinal canal; and the arachnoid, a delicate web-like structure lying between the pia and dura. The term meningitis is specifically applied to an inflammation of the pia mater of the brain, described in this article under the heading of Cerebral Meningitis. Inflammation of the dura, whether of the brain or cord, is called pachymeningitis, and of the pia, leptomeningitis. The term arachnitis was formerly used on the supposition that the arachnoid might be the seat of an independent inflammatory process, but this is no longer believed to be possible, An inflammation involving the meninges of both the brain and cord is termed cerebro-spinal meningitis. For convenience of description the subject may be arranged under the following heads: Pachymeningitis, involving the dura of the brain and cord; cerebral meningitis, of which two forms are recognized: tubercular and simple; spinal meningitis, and epidemic cerebrospinal meningitis.
Pachymeningitis. The dura becomes inflamed on its outer surface from injuries, or by extension from adjacent structures. In the head a common cause is suppurative disease of the middle ear (see Ear, section Diseases), and in the spinal dura a very frequent cause is caries of the vertebræ. The internal surface of the dura is the seat of a peculiar hemorrhagic inflammation, hæmatoma of the dura mater, characterized by the formation of adventitious membranes, which appear to be repetitions of the arachnoid, having blood-vessels which rupture, the extravasated blood collecting in the form of cysts containing from an ounce to a pound of blood. The symptoms of this hemorrhagic form of pachymeningitis are primarily those of inflammation and secondarily due to pressure. There is some fever, irregularity of the pulse, headache, giddiness, somnolence, gradually deepening to coma; and there may be twitch-
