GULF STREAM. 365 GULL. Gulf Stroam is a result of the goncral vertical circulation of the eccan, bringing from tlic nortli cold water which sinks below, while the warm Wiiter of the equatorial region rises, and slides northward above the cold current; owing to the rotation of the earth, each of these currents de- viates toward the right, so that the cold cur- rent presses toward the suulhwest and the sur- face current toward the northeast. These pres- sures are very slight, but by acting for long ages they have given the upper layers of the ocean a slight general rotation. r>y thus being pushed against the shores or through narrow channels, the mass of water far below the influence of sur- face winds is forced to seek its channel of easiest flow, and the cold water ilowing through certain passages between the cst Indian Inlands into the Caribbean Sea Hows thence into the Gulf of Mexico, and finally it rounds Cape Sable as warm water from the gulf. The Gulf Stream really has its origin in deep currents far east of the indward and Leeward Islands, and is pressed northward beyond Cape Sable by the force of the water pushing behind it from the Atlantic Ocean into and through the Caribbean Sea. In other parts of the globe there are great ocean currents that depend wholly upon the winds, but tins does not seem to be Ihe case with the Gulf Stream. BiDLiOGR.iPHY. Ferrel, Winds of the Gloie (Xew York. lS9o) ; Agassiz. Three Cruises of ihe Blake (Boston. 1888): Pillsbury. in Antiual Report, published by the Ignited States Coast Survey (Washington, 1800) : Thomson and Blake, Reports of the t^cieniific Results of U. M. S. Chailf lifter (London. 1880-0.5). GULFWEED. A popular name of Sarrtns- sum, one of the brown alg;T. The plants are torn from the coast and carried by currents out to sea. where they grow and form large masses of iloating weed in the eddies of oceanic currents. See Pn.T:opiiYCE.5:. GULISTAN, grio'le-stan' (Pers., rose-garden). The most famous work of the Persian poet Sadi (q.v.), a collection of moral discussions inter- woven with stories, puns, and maxims. It is contained in eight chapters in prose and verse. There are English translations bv Eastwick (Hertford. 18.52) ; Gladwin (Boston.' 1S0.5) ; and Sir Edwin Arnold (London. 1890). GULL (from Corn, gullan, Welsh gn-i/lnn, Bret, riirelaii. gull). A web-footed bird of the subfamily Larin.T, of the family Laridse. The gulls are inhabitants of the seacoasts of all parts of the world, and also of the shores of large rivers and lakes far inland. The bill is strongly hooked at the tip. tlnis differing from that of the terns, and lacks a cere, in this respect dif- fering from that of the jiigers. The tail is usual- l.v square across the tip. and the wings are long and pointed. The plumage is generally in great part white, variously mixed with gray, slate- color, brown, and black. The white in some species assumes a rosy tint in the breeding sea- son, and the head of some becomes black. The differences of plumage, according to age. season, and sex. are verj^ considerable, and have led to many errors as to species. Gulls have great power of wing, and delight in performing varied and beautiful evolutions. They descend with great rapidity to seize prey from the surface of the water, or at a small depth ; but they are not good divers, and the Hsiics caught are chiefly those whidi, like tlic herring, swim near the sur- face. They are very voracious. Tludr food con- sists of almost anything animal, and they fre- quently rol) other birds' nests of eggs or young. In winter tlicy throng harbors, and fee<l largely on scraps thrown from ships or drifted upon the shores. The larger gulls seize clams and other mollusks, carrying the large oms into the air and dri)])ping tlicm upon a rock in order to break them. The llesh of gulls is rather coarse, but that of the .young is in request on many n(]rthern coasts as an article of food, and is salted for winter use. The eggs are palatable, and are collected in great quantities in some places. All gulls are wholly or partially migratory; they breed in colder regions than those which they inlial>it in winter. In general, they lay only two or three eggs, which are large for the size of the bird, bluish-white to brownish- olive in color, more or less heavily spotted, blotched, and marked with brown. Idack, and purplish. The nest is composed of moss and seaweeds, or marsh-weeds, and is usually on the ground in swamps or on rocky cliffs. Occasion- ally, however, the nest is built in trees, and is then based on a foundation of sticks. About 50 species of gulls are known, of which about 20 are found in Xortli America. The com- monest and most widclj- distributed are the ring- billed gull (Larus Urlim-nrcnsis) and the herring gull (Larus argentutus, var. Hinitlisonianus) . The latter is two feet long and nearly five feet across the wings, while the former is considerably smaller. Both species are abundant on the Atlantic coast, in the Mississippi Valley, and about the Great Lakes. They breed from the United States northward. The kittiwake (Rissa triflacti/la) . rather smaller than the first named, gray and white, and destitute of a hind toe. is plentiful in Arctic America and Europe, where the coast is girt with rocky precipices, on the narrow ledges of which it makes its nest. Its young and eggs are among the chief objects of pursuit of the rock-fowlers. The great black- backed gull, or 'wagell' (Larus marinus) , nearly thirty inches long, is found on the Atlantic coasts of both Europe and America; and the glaucous gull, or 'burgomaster' (Larus filniiriis). scarcely inferior to it in size, of a pale bluish-gray cidnr above and white below, is a winter visitant from the Arctic regions. On the Pacific coast of Xorth America, the common gulls are the glaucous-winged gull (Larus glaueescens) , the Californiai gull (Liiriis Califoriiieiis) . and the western herring gull {I Aims occidciitdlis) . all large birds, four feet and a half across the wings. Smaller than these is the white- headed gull (Larus nreriiiaiiiii) . which is leail- colored, with a white head and red bill; it is common on the coast of California. Other notable gulls are the common mew (Larus eauus) of Europe: the red-legged kittiwake (Rissa hreri- rostris) of Bering's Sea; the Arctic ivory gull (Larus aiha). the entire plumage of which is pure white: the black-headed gulls of Europe and America (Larus ridihiiiiilus and alricilla); Franklin's and Bonaparte's rosy gulls (Larus Fraiil-liui and I'liiladrlphia) . the white under parts tieing suffused with rose during the breed- ing season; Ross's rosy gull (Rhodnslrlhia rosea) , which has a wedce-shaped tail, and is white, rosy tinted, with a black collar, and occurs only in the
