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610 GANGES bad it is a mile wide, while the width of the Jurnna is but 1,400 yards. From this city down to the head of the delta the river is navi- gable throughout the year for vessels drawing 18 in. of water. The greatest breadth ordi- narily attained at Benares, 75 m. below Allaha- bad, is 1,000 yards and the maximum depth 78 ft. ; in the dry season these figures are re- duced to 1,400 ft. and 35 ft. respectively. The course and current of the river, especially in its lower portion, are extremely subject to change. Old channels are filled up and aban- doned for new ones which the action of the water has excavated ; new islands are formed around sand bars or sunken objects which serve as nuclei for mud deposits ; and at the same time old islands are being swept away. The Hoogly is the only arm which can be ascended by large ships for any considerable distance. Opposite Calcutta it is about 1 m. wide at high water. The coast region of the delta of the combined rivers Ganges and Brahmapootra con- sists principally of a vast labyrinthine network of salt-water streams and creeks. Fresh-water channels, however, communicating with the Hoogly, intersect the extensive wilderness of wooded islands along the coast, known as the Sunderbunds. This pestilential tract has an area of more than 7,000 sq. m., and is haunted by innumerable crocodiles, tigers, and other wild animals. In the Sunderbunds the ordi- nary rise and fall of the tide is between 7 and 8 ft. When the Ganges is low, the tidal cur- rent extends as far inland as the head of the delta, but in the flood season it is overcome by the increased volume and velocity of the river, and is imperceptible except near the coast. The whole delta district is subject to inundation during the annual rise of the river. A tract of the Lower Provinces 100 m. in width is The Source of the Ganges. then completely covered with water, which re- cedes in October, when the rice crop is plant- ed. These inundations become very destruc- tive if the descending current of the river flood happens to be checked by high tides and strong gales in the bay of Bengal. The quantity of fine mud and sand brought down by the Ganges and Brahmapootra is so large that it discolors the sea to a distance of from 60 to 100 m. from the delta. At Ghazepoor, 500 m. from the sea, 500,000 cubic feet of water per second flow down the Ganges during the four months of the flood season, and about 100,000 cubic feet per second during the rest of the year. In 1831-'2 the total amount of solid matter sus- pended in the water thus flowing down was estimated to be 6,368,077,440 cubic feet in a year. Lyell's estimate of the entire quantity of mud borne down to the bay of Bengal in one year by the Ganges and Brahmapootra is 40, 000 millions of cubic feet. In this calculation he assumes that the annual water discharge of the latter river is equal to that of the Ganges, and that the proportion of sediment in both rivers is about a third less than the Ghazepoor estimate. Geological borings at Calcutta indi- cate that a general subsidence of the delta has taken place. To this subsidence is attributed the fact that the fluviatile mud which is de- posited by successive inundations does not in- crease the elevation of the plains of Bengal. Three well marked species of crocodile infest the Ganges in great numbers. The gavial, which is the characteristic Gangetic crocodile, lives only in fresh water and feeds exclusively on fish. Its range extends from the delta to the northern branches of the river, 3,000 m. from Calcutta. The other kinds, known as the