Madagascar

MADAGASCAR, an island in the Indian ocean, after Green land, New Guinea, and Borneo, the largest island in the world, about 400 km. distant, on an average, from the south-east coast of Africa, from which it is separated by the Mozambique channel. Since 1896 Madagascar has been a French colony. It is 995 m. in length from north to south, and about 25o m. in average breadth, although, near the centre, it is nearly 36o m. across ; its area is about 228,000 sq. miles. It lies mainly between and 50° E. Its northernmost point, Cape Ambro, in 12° S., inclines 16° to the E. from the longitude of Cape St. Mary, the southern most point, in 25° 35' S., so that the main axis of the island runs from north-north-east to south-south-west. There is a cen tral plateau, roughly quadrilateral in shape, from 3,00o to 5,000 ft. in altitude, around which are extensive plains at a much less elevation above the sea, and most developed on the western and north-east sides. But this lower region is broken up by masses of hills, with several elevated plateaux, especially in the south-west and south.

Geology.

Madagascar was probably joined to Africa, possi bly until Triassic times, thus forming part of the Gondwana con tinent, but the splitting off is very ancient, and bordering islands, such as the Seychelles, etc., allow of the conclusion that the island belonged to a continent called by the geologists Lemuria, from the lemurs which still inhabit the island, and stretching as far as India. The sinking which brought about the disappearance of this continent gave rise to violent volcanic eruptions, which ex plain the abundance of basalts in the Amber mountains and in the Ankaratra mountains, 2,00o sq.m. of which are lava covered. These ancient volcanoes are found along a line, following a line of fracture, in the east centre of the island, but they are present also in the western side. Itasy is a more recent Tertiary volcano. Thermal springs, "Ranu-mafana" (warm water), such as those of Antsirabe are numerous, and slight earthquakes are frequent.

The subsoil of the island is formed of crystalline schists and of gneiss and associated rocks, metamorphic and other; granites, porphyries, etc. Iron is very abundant and is used for native industry, as is gold. which is found throughout the zone of crys talline rocks, especially in the eastern part of the island. Other

metals exist in small quantities, such as graphites and numerous precious stones, etc.

Two-thirds of the surface soil of the island is made up of laterites, which cover the high plateaux; compact and dry, they are not very fertile. The western part of the island is formed of stratified sedimentary rocks. The plateaux of Antankara are formed of limestones, sandstones and clays of Jurassic to Tertiary origin. The Jurassic limestones form, in places, karst areas.

The lake alluvium of the depressions and the alluvium of the coastal plains are very fertile, and an arborescent vegetation grows on all the Tertiary sedimentary outcrops.

Palaeontology.

Bones of 12 species of struthious birds have been found in a sub-fossil state. They belonged to two genera, Aepyornis and Mullerornis, which varied in size from that of a bustard to birds much exceeding an ostrich, and rivalling the re cently extinct moa of New Zealand, the largest species being about io ft. in height. One species of these great wingless birds laid an egg which is the largest known, being 121 in. by 91 inches. Associated with these remains there have been found those of many other birds, some of these being much larger than any now inhabiting Madagascar. In the same beds remains of two or three species of hippopotamus have been found, about two-thirds the size of the living South African species ; also the bones and cara pace, etc., of gigantic tortoises, and the bones of crocodile, now extinct on the coast and rivers, but still living in the two chief lakes; also the remains of a river-hog, of a species of swine and of a slender-legged form of zebu-ox. Near the south-west coast the skull of a large lemuroid animal was discovered in 1893, much longer than that of any living lemur, the animal being probably three times the size of any previously known Madagascar lem- I uroid. Later still, the bones of two other lemuroids have been discovered, one of them indicating an animal much larger than a man. Many of these birds and animals were probably con temporaneous with the earliest human inhabitants of Madagascar. The remains of two species of Edentata have been found, as well as those of several species of small Rodents, also of a Carnivore (Cryptoprocta), a larger variety of the species. still living in the island.