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Bible Encyclopedias
Shari
1911 Encyclopedia Britannica
or an important river of North-Central Africa, carrying the drainage of a large area into Lake Chad (q.v.). Its headstreams rise on the watersheds between the Lake Chad basin and those of the Nile and Congo. The principal headstream, known variously as the Wahme, Wa, Warn or Worn, rises, in about 6° 30' N., 15° E., in mountainous country forming the divide between the Chad system and the basin of the Sanga affluent of the Congo.
The Warn flows east and then north and in about 7° 20' N., 18° 20' E. is joined by the Fafa, a considerable stream rising east of the Wam. The upper course of the Warn is much obstructed by rapids, but from a little above the Fafa confluence it becomes navigable. Below the confluence the river, now known as the Bahr Sara, receives three tributaries from the west. In about 9° 20' N., 18° E., it is joined by the Bamingi, which is formed by the junction of the eastern headstreams of the Shari. The Bamingi, before the exploration of the Warn, was thought to be the true upper course of the Shari. One of its branches, the Kukuru, rises in about 7° N., 21° 15' E. Some 90 m. from its source the Bamingi becomes navigable, being 12 ft. deep and flowing with a gentle current. In 8° 42' N. it receives on the west bank the Gribingi, a river rising in about 6° 20' N. It is narrow and tortuous with rocky banks and often broken by rapids, but navigable at high water to 7° N. It flows in great part through a forest-clad country. A few miles above its confluence with the Bahr Sara the Bamingi receives on the right hand another large river, the Bangoran, which rises in about 7° 45' N. and 22° E., in a range of hills which separates the countries of Dar Runga and Dar Banda, and, like the Bamingi, flows through open or bush-covered plains with isolated granite ridges.
Below the junction of the Bahr Sara and the Bamingi the Shari, as it is now called, becomes a large river, reaching, in places, a width of over 4 m. in the rains; while its valley, bordered by elevated tree-clad banks, contains many temporary lakes and back-waters. Its waters abound with hippopotami and crocodiles, and the country on either side with game of all kinds. In 9° 46' N. it receives the Bakare or Awauk (Aouk) from the east, known in its upper course as the Aukadebbe. This, like the Bahr es Salamat, which enters the Shari in 10° 2' N., traverses a wide extent of arid country in southern Wadai, and brings no large amount of water to the Shari. In 10° 12' a divergent branch, the Ergig, leaves the main stream, only to rejoin it in 11 ° 30'.
In 12° 15' N. and 15° E. the Shari receives on the west bank its largest tributary, the Logone, the upper branches of which rise far to the south between 6° and 7° N. The principal headstreams are the Pende and the Mambere. The Pende rises some 30 m. N. by E. of the source of the Wam. It flows northwards through a fertile valley and in 9° 35' N. and 16° E. is joined by the Mambere, which rises in the hills of Adamawa and flows in a course roughly parallel to the Pende. Below the junction of the Pende and Mambere the Logone is a broad and deep river. Its system is connected with that of the Benue (see Niger) by the Tuburi Swamp, which sends northward a channel joining the Logone in about ¶0° 30' N. Below the Logone confluence the Shari, here a noble stream, soon splits up into various arms, forming an alluvial delta, flooded at high water, before entering Lake Chad. From the source of the Warn to the mouth of the river is a distance, following the windings of the stream, of fully 1400 m.
The existence of the Shari was made known by Oudney, Denham and Clapperton, the first Europeans to reach Lake Chad (1823). In 1852 Heinrich Barth spent some time in the region of the lower Shari and Logone, and in1872-1873Gustav Nachtigal studied their hydrographical system and explored the Gribingi, which he called the Bahr el Ardhe. It was not, however, until the partition of the Chad basin between Great Britain, France and Germany (1885-1890) that the systematic exploration of the Shari and its affluents was undertaken. The most prominent explorers have been Frenchmen. In 1896 Emile Gentil reached the Bamingi and in a small steamer passed down the river to its mouth. The existence of the Bahr Sara had been made known by C. Maistre in 18 9 2, and in 1894 F. J. Clozel discovered the Wam. In 1 9 00 A. Bernard demonstrated the identity of these two streams. In 1907 an expedition under Captain E. Lenfant followed the Wam-Bahr Sara from its source to the confluence with the Bamingi and showed it to be the true upper course of the Shari. The same expedition also discovered the Pende tributary of the Logone. Captain Lenf ant had previously demonstrated (1903) the connexion between the Benue and Logone. From the mouth of the Shari in Lake Chad there is a current towards the Bahr-el-Ghazal channel at the south-eastern end of that lake. This channel has been supposed to be a dried-up affluent of the lake (see Chad). Investigations by the French scientists E. F. Gautier and R. Chudeau led Chudeau to the conclusion that the Shari did not end in Lake Chad, but, by way of the Bahr-el-Ghazal, passed between Tibesti and Ennedi and ended in some shut in the Libyan desert. That the Shari may have reached the Nile is an hypothesis not absolutely rejected. (See Missions au Sahara, tome ii. (Paris, 1909), and for theories as to the Niger-Nile connexion see Niger.) From the spot where it is intersected by 40 N. to Lake Chad the Shari forms the boundary between the German colony of Cameroon and French Congo. The best route from the Congo to Lake Chad is via the Sanga affluent of the Congo to the station of Carnot, and thence across the watershed to the Pende.
See the works of Barth, Nachtigal and other travellers, especially Lenfant's La Decouverte des grandes sources du centre de l'Afrique (Paris, a Selachian fish (see Selachians), belonging to the order Plagiostomi, suborder Squali.
Sharks are almost exclusively inhabitants of the sea, but some species enter the mouths of large rivers, and one species (Carcharias gangeticus) occurs frequently high up in the large rivers of India. C. nicaraguensis of the lake of Nicaragua and the Rio San Juan appears to have taken up its residence permanently in fresh water. Sharks are most numerous between the tropics, a few only reaching the Arctic circle; it is not known how far they advance S. in the Antarctic region. Altogether some hundred and fifty different species have been described.
With regard to their habits many are littoral species, the majority pelagic, and a few are known to belong to the deep-sea fauna, having hitherto been obtained down to a depth of nearly loon fathoms. Littoral Sharks. - The littoral forms are of small. size, and generally known under the name of "dog-fishes," "hounds," &c. Some pelagic sharks of larger size also live near the shore on certain parts of a coast, but they are attracted to it by the abundance of food, and are as frequently found in the open sea, which is their birthplace; therefore we shall refer to them when we speak of the pelagic kinds.
The majority of the littoral species live on the bottom, sometimes close inshore, and feed on small marine animals or on any animal substance. The following are deserving of special notice. The tope (Galeus) is common on the coasts not only of England, Ireland and of S. Europe, but also of S. Africa, California, Tasmania and New Zealand. Its teeth are equal in both jaws, of rather small size, flat, triangular, with the point directed towards the one side, and with a notch and denticulations on the shorter side (fig. i). It is of a uniform slaty-grey colour, and attains to a length of 6 ft. The female brings forth some thirty living young at one birth in May. It becomes troublesome at times to fishermen by taking their bait and driving away other fish they desire to catch. The fins of G. zyopterus of the Californian coast are much esteemed for culinary purposes by the Chinese.
The hounds proper (Mustelus) possess a very different dentition, the teeth being small, obtuse, numerous, arranged in several rows like pavement (fig. 2). Five or six species are known from the shores of the various temperate and subtropical seas, one (M. vulgaris) being common on the coasts of Great Britain and the United States, on the Pacific as well as the Atlantic side. It is of a uniform grey colour or sparingly spotted with white, and attains to a length of 3 or u FIG. 1. - Teeth of Tope. u, Upper; 1, lower. (X 2.) FIG. 2. - Teeth of Mustelus. 4 ft. The young, about twelve in number, are brought forth alive in November. It is comparatively harmless and feeds on shells, crustaceans and decomposing animal substances.
The dogfishes proper (Scyllium, Chiloscyllium, &c.) are spread over nearly all the temperate and tropical seas. Their teeth are small, in several series, with a longer pointed cusp in the middle, and generally one or two smaller ones on each side (figs. 3 and 5). They are all oviparous, their oblong egg-shells being produced at each corner into a long thread by which the egg is fastened to some fixed object. Some of the tropical species are ornamented with a pretty pattern of coloration. The two British species,the lesser and the larger spotted dogfish (Sc. canicula and Sc. catulus), belong to the most common fishes of the coast and are often confounded with each other. But the former is finely dotted with brown above, the latter having the same parts covered with larger rounded brown spots, some of which are nearly as large as the eye. As regards size, the latter exceeds somewhat the other species, attaining to a length of 4 ft. Dogfishes may become extremely troublesome by the large numbers in which they congregate at fishing stations; they are rarely used as food, except in the Mediterranean countries, in China and Japan, and in the Orkneys, where they are dried for home consumption. The black-mouthed dogfish (Pristiurus melanostomus) is rarely caught on the British coasts, and is recognized FIG. 4. - Chiloscyllium trispeculare. by a series of small, flat spines with which each side of the upper edge of the caudal fin is armed.
The tiger-shark (Stegostoma tigrinum) is one of the commonest and handsomest sharks in the Indian Ocean. The ground colour is a brownish-yellow, ornamented with black or brown transverse bands or rounded spots. It is a littoral species, but adult specimens, which are from 10 to 15 ft. long, are met far from land. It is easily recognized by its enormously long bladelike tail, which is half as long as the whole fish. The teeth are small, trilobed, in many series. The fourth and fifth gill-openings are close together.
The genus Crossorhinus, of which three species are known from the coasts of Australia and Japan, is remarkable as the only instance in this group of fishes in which the integuments give a "celative" rather than a "protective" resemblance to their surroundings. ' Skinny frond-like appendages are developed near the angle of the mouth, or form a wreath round the side of the head, and the irregular and varied coloration of the whole body closely assimilates that of a rock covered with short vegetable and coralline growth. The species of Crossorhinus grow to a length of io ft.
The so-called Port Jackson shark (Heterodontus = Cestracion) is likewise a littoral form. Besides the common species (H. philippi), three other closely allied kinds from the Indo-Pacific are known. This genus, which is the only existing type of a separate family, is one of special interest, as similar forms occur in Primary and Secondary strata. The jaws are armed with small obtuse teeth in front, which in young individuals are pointed, and provided with from three to five cusps. The lateral teeth are larger, pad-like, twice as broad as long and arranged in oblique series (fig. 7). The fossil forms far exceeded in size the living, which scarcely attain to a length of 5 ft. The shells of their eggs are found thrown ashore like those of our dogfishes. The shell is pyriform, with two broad lamellar ridges each wound edgewise five times round it (fig. 8).
The spiny or piked dogfish (Acanthias) inhabits the temperate seas of both the N. and S. hemispheres. For some part of the year it lives in deeper water than the sharks already noticed, FIG. 6. - Heterodontus galeatus. but at uncertain irregular times it appears at the surface and close inshore in almost incredible numbers. Couch says that he has heard of 20,000 having been taken in a seine at one time; and in March 1858 the newspapers reported a prodigious shoal reaching W. to Uig, whence it extended from 20 to 30 m. seaward, and in an unbroken phalanx E. to Moray, Banff and Aberdeen. These fishes are distinguished by each of the two dorsal fins being armed in front by an acute spine. They do not possess an anal fin. Their teeth are rather small, placed in a single series, with the point so much turned aside that the inner margin of the tooth forms the cutting edge (fig. 9). The spiny FIG. 7. - Upper Jaw of Port Jackson Shark (Heterodontus philippi). (X 2.) dogfish are of a greyish colour, with some whitish spots in young specimens, and attain to a length of 2 or 3 ft. They are viviparous, the young being produced throughout the summer months.
Finally, we have to notice among the littoral sharks the "angel-fish" or "monk-fish" (Rhina squatina), which, by its broad flat head and expanded pectoral fins, approaches in general appearance the rays. It occurs in the temperate seas of the S. as well as the N. hemisphere, and is not uncommon on sandy parts of the coast of England and Ireland. It does not seem to exceed a length of 5 ft., and is too rare to do much injury to other fish. It is said to produce about twenty young at a birth.
