GUINEA.) The fundamental feature in the geological structure of Asia appears to be the presence in the north and in the south of large areas which have remained relatively rigid since the beginning of the Cambrian period, while between and around them folding of mountain-building type has taken place at different dates.
The southern portion of the region thus defined consists chiefly of a platform of Cambrian and Ordovician beds, which are gen erally horizontal or nearly so. The deposits are mostly marine, but red sandstones and gypsum in the Ordovician suggest salt lakes. These Lower Palaeozoic beds are overlaid in places by plant-bearing beds of terrestrial origin, to which Suess has given the general name of the Angara series. The series, which is widely spread in northern Asia, probably ranges from the Per mian to the Cretaceous, but in Siberia the deposits are mostly Jurassic.
While the southern portion of the area thus seems to have been land since the later part of the Palaeozoic era the sea at times overspread it from the north at least as far as 62° N., but not con tinuously. Marine deposits of various Jurassic and Cretaceous horizons have been found, but there is no indication of marine Trias such as occurs in the Verkhoyansk range.
Extensive flows of basic lava cover a wide area, with little indication of actual volcanoes. The age of the flows is uncertain. They may be Cretaceous or Tertiary.
Most of the north-western part of the peninsula is covered by a thick series of basaltic lava flows, known as the Deccan Trap, which occupies an area of about z5o,000sq.m. Very little evidence of any explosive action has been found and the erup tions took place from fissures. They belong either to the later part of the Cretaceous or the early part of the Tertiary period. The fact that this series, several thousand feet in thickness, is abruptly cut off at the western coast is a clear proof that the land mass formerly extended much farther in that direction than it does at present.
In Syria and north-western Arabia several high-lying plateaux are formed of basic lava-flows, but they are not comparable with the Deccan Trap of India in extent and seem to be of later date. Probably the eruptions took place largely from fissures, but towards the western edge of the Arabian plateau there are many small volcanic cones which are still nearly perfect, and there is a record of an eruption east of Medina in A.D. The great belt of folding which runs from Asia Minor to the coast of China occupies the site of an ancient sea which lay between the northern and the southern massifs and which Suess named "Tethys." Marine deposits play a much larger part than upon the massifs and the geological succession is much more complete. Folding took place at various periods and the effects of the different periods have not yet been disentangled. From the Tien Shan and Kunlun northwards and also in south-eastern China the chief folding took place during the Palaeozoic era. The Caledonian system of Europe may perhaps be represented in the ranges near the Siberian massif, but this is still uncertain. The Hercynian system is dominant in the Tien Shan, the Kunlun and in China. But it must not be supposed that the present mountain ranges are the direct consequence of this ancient fold ing. The old ranges have been worn down and broken up and the actual topography is largely due to a remarkable system of trough f aulting of much later date.
Farther south the principal folding is of Tertiary age and belongs to the Alpine system. The southern limit is marked by the depression of Mesopotamia, the Persian gulf and the Indo gangetic plain. The whole mass is being pushed forward over the rigid regions of the south and is crumpling in the process. Simi larly the Burmese ranges, which are of about the same age, were produced by crushing against the eastern border of the Indian massif.
Although the Alpine system of earth movements is believed to have culminated in the Tertiary period, there is clear evidence of an earlier and independent phase. In the Oman zone already referred to, the principal movements took place during the earlier part of the Cretaceous period. Movements of the same age occur in central Persia, and it is not impossible that the folding of the Ural mountains may have taken place about this time. The latter is usually referred to the Hercynian system but on very imperfect evidence. All that is really proved concerning it is that a part of the Russian Permo-Carboniferous is involved and that the folding was completed before the deposition of the Upper Cretaceous. Whether there was any connection with the Urals or not it seems clear that in western Asia an earlier Cretaceous folding cuts across the line of the later Tertiary movements, and much work will be necessary before the effects of the two phases are un ravelled.
Movement in the Himalayas and in other parts of the Alpine system has not yet entirely ceased, but the island arcs off the east coast of Asia seem to belong to a system which has not even reached its culmination. Wegener has attributed them, in a vague way, to a dragging effect as the continent drifted westward. Judging from the history of other mountain arcs they must have been produced by the thrusting of Asia against and over the floor of the Pacific, which seems to function as a rigid area. The great deeps which lie outside the island arcs would then corre spond with the depressions common on the convex side of moun tain arcs, such as the Persian gulf and the deep hollow filled by the deposits of the Indus and Ganges.
It is common ground to all geologists that the folded belt of Asia has been produced by lateral compression, and this compres sion implies that the rigid regions of the north and the south have approached one another; but there are differences of opinion as to the cause of this approach. Suess would attribute it to con traction of the earth's interior, Wegener to movement of sial masses floating in the sima. The former hypothesis supplies a force of ample power, but whether the amount of contraction has been sufficient cannot be finally determined until we know more about what happens in the interior of the earth. The latter allows movement of the required extent : it has not yet provided a force capable of lifting the floor of the sea to the level of central Asia against the force of gravity. (P. LA.) The great area of Asia and its extension from 7 7 ° N. at Cape Chelyuskin almost to the Equator at Singapore, give this con tinent a very great range of climates. It may conveniently be divided into four sections, Siberia and western Turkistan ; south west Asia ; India and Farther India; China and Japan; but even in these smaller areas the range is still very great.
Siberia and Western Turkistan.—This section extends from the Urals and the Caspian to the Pacific, and from the Arctic ocean to the great mountain ranges of central Asia—Tien Shan, Altai and Yablonoi mountains. The southern part is occupied by extensive steppes, becoming true desert in Turkistan. North of this is a belt of forest, succeeded by the tundras of the Arctic coast. The climate is characterized by a remarkably clear cold winter and a hot summer, which is the chief rainy season. In the west the moderating effect of the Atlantic can be traced at times as far as the Yenisei, the Urals not being high enough to act as a marked climatic divide, but in the east a temperate mari time climate is only found in the peninsula of Kamchatka.
In winter Siberia is occupied by a vast anticyclone, in which the highest known pressure on the globe (1,072 millibars re duced to sea level) was recorded at Irkutsk on Dec. 20, 1896. The intensity of the anticyclone is mainly due to the severity of the cold, forming a great pool of cold air, but the basin-like topography of the Baikal region is also an important factor by preventing the cold air from flowing away, hence the centre of the anticyclone is found south of Irkutsk instead of at the "cold pole" near Verkhoyansk. From this anticyclonic centre an axis of high pressure extends towards the Black sea in the west and Bering strait in the east ; to the north of this axis the winds tend to be westerly, and to the south of the axis, easterly. Winds are in general light in the interior, but violent blizzards termed poorgas and buran occur, often causing loss of life. In the main river valleys the cold air flows down the valleys irrespective of direction. On the east coast strong, very cold, northerly winds prevail. The anticyclone lasts from September to April inclu sive ; in June, July and August it is replaced by a large shallow area of low pressure over eastern Siberia and China, and south easterly winds prevail over eastern Siberia, bringing much cloud and a moderate rainfall, while over western Siberia the winds are mainly north-westerly.
Northern Siberia is among the coldest regions on the surface of the globe, the Lena delta having an average annual temperature of i° F, while the isotherm of 32° reaches 49° N. (the latitude of Jersey) near Kharbarovka. The annual variation is extreme over the interior, the winters being frightfully cold and the sum mers comparatively hot. Verkhoyansk, with an average Janu ary temperature of —59° F and an extreme of —94° F, has the coldest winter of any permanently inhabited portion of the globe. Other average January temperatures are —46° F at Yakutsk, — 6 ° F at Irkutsk, — 9 ° F at Yeniseisk, — i 4 ° F at Obdorsk and — 5 ° F at Omsk, and almost everywhere extremes of — 5o° F are recorded. These temperatures sound appalling but are bearable because of the extreme dryness of the air and the general absence of wind. The hard dry snow surface is ex cellent for sleighs, and winter is the favourite season for travel. The effect of the winter on vegetation is negligible, and in parts of Siberia plants thrive in the open which in England need the pro tection of a glasshouse; this is because the temperature rises so rapidly in spring that once the growing season begins there is no further danger of frost. The summer is short, but in the in terior it is hot, the average July temperature exceeding 6o° F over most of Siberia. The mean daily range is about 15° F in winter but 25° F in summer; the highest temperatures frequently exceed i oo° F and I i 3 ° F has been recorded at Olekminsk. On the Arctic coast the summer consists of two months of cool, foggy, dismal weather. Turkistan has moderately cold winters, with an average temperature of about 3o° F in January, and ex tremely hot summers, the July temperature at Tashkent being 8o° F.
The annual rainfall is less than loin. a year over the tundras and again in southern Siberia, falling below 4in. in parts of Turkistan. The rainiest regions are the forest belt of western Siberia and south-eastern Siberia, with coin. qr more, and south ern Kamchatka with 4o inches. The precipitation in winter is everywhere small, and is entirely in the form of snow; spring is the wettest season in Turkistan but is dry elsewhere. Sum mer has fairly heavy rains over the whole of Siberia, while southern Kamchatka has its rainy season in autumn.
South-west Asia.—This area includes Asia Minor, Syria and Palestine, Arabia, Mesopotamia, Persia and Afghanistan. We may sub-divide it into three belts, a northern belt of plateaux and mountains, an intermediate belt of steppe and desert, and the south coast. The northern belt, including Asia Minor, Armenia and the highlands of Persia and Afghanistan, has a climate re sembling that of the Spanish plateaux but drier and more severe. The winters are cold, with a moderate but irregular snowfall, and the summers are hot and dry. Thus Angora has a tempera ture of 31 ° F in January and 71 ° F in July and August, the extremes are i oo° F and —13° F and the annual precipitation is only 9 inches. The prevailing winds are north-easterly. The western and southern coasts of Asia Minor and the northern part of the Syrian coast have much warmer winters and a greater rainfall, reaching 36in. at Beirut. Farther east the rainfall in this belt is generally between i o and coin. a year, and the tempera tures at heights of 5,00o to 6,000ft. range from 32° F in January to 8o° F in July.
The steppe and desert belt includes Syria, most of Arabia, southern Mesopotamia and the greater part of Persia. Owing to its lower elevation, the temperatures are higher than in the plateaux, but cold weather is often experienced in winter; heavy snowfalls have occurred in Jerusalem and even the northern part of the Arabian desert has been seen carpeted with snow for many miles. At Baghdad a temperature of 19° F has been recorded. In summer the heat is intense, the average temperature exceed ing 9o° F in July and August, while the extremes exceed i io° F almost every year and i 23° F has been recorded at Baghdad. The prevailing winds are northerly throughout the year (except in Palestine, where they are westerly) and are sometimes of great strength, especially in summer. Strong dust-laden northerly winds are termed Sharnal in Mesopotamia and Persia. The prov ince of Seistan in eastern Persia is noted for the Seistan or "wind of r 20 days" (June to September) which often exceeds Tom. per hour and has reached i 20 miles. In southern Palestine and Arabia the Sirocco occurs as a dry dust-laden south-east wind. The rainfall averages about coin. a year in the west but decreases eastwards, and in Arabia, Mesopotamia and eastern Persia there are large desert areas with less than coin., often less than tin. a year. The rainfall is limited to the winter and spring months and is very variable from year to year. The southern Red sea, the south coast of Arabia and the Persian gulf have a moister climate with frequent south-west winds in summer and some rain at that season. The winters are very mild (Aden January aver age 76° F) and the summers are characterized by a moist heat, which is very unpleasant, especially in the Persian gulf.
India.—In India the year falls into three seasons, the cold weather, the hot weather and the rains. The "cold weather" ex tends from November to March, January being the coldest month with temperatures (reduced to sea-level) rising from 55° F in the north-west to nearly 8o° F over Ceylon, the average for the whole country being 67.5° F. There is some rain in the north west, brought by storms which have come from the Mediterra nean across Persia ; Ceylon also has an appreciable rainfall, brought by the prevailing north-east trades blowing across the Bay of Bengal, but the greater part of India is dry. In March and April temperature rises rapidly, and April, May and June are very hot, the average temperature of the whole country being 87° F, and exceeding 95° F in central India in May and in the north-west in June. The dry weather lasts through May and the early part of June, but heavy rain begins to fall towards the end of June; July and August are generally the wettest months, but the rain continues through the greater part of September. The cloudy skies and rain lower the temperature over most of India, and the average for July, August and September is only 83° F. In the north-west the rainfall is very small, and temperature is much higher, averaging 99° F at Jacobabad in June and 97° F in July, while a maximum of i 26° F has been recorded. Owing to the vertical decrease of temperature at the rate of 3° F per i,000ft., stations at a height of several thousand feet have a pleasant climate during the hot weather on the plains, and are employed as summer resorts. The prevailing winds are north-easterly from October to February, irregular in March, and south-westerly from April until September. The north-east winds are naturally dry (except in Ceylon) ; during April and May the south-west winds are also dry, because they originate as northerly winds in Persia, curving round the Arabian sea. Towards the end of June there is a change in the general pressure distribution ; the south-west erly winds over India originate in the south Indian ocean and arrive heavily charged with moisture. The north-east and south west winds are termed monsoons, but owing to the economic im portance of the summer rains, the term monsoon is often applied to the rainy season and not to the wind. The winds are generally light, except during the passage of cyclones.
The distribution of rainfall over India is very irregular. The heaviest falls occur where the rain-bearing winds strike directly against high ground, and the amount exceeds l ooin. a year over the whole stretch of Western Ghats from Cochin to beyond Bombay, in central Ceylon, the whole coast of Burma, and the high ground in Assam and Bhutan. The Khasi hills in Assam are reputed to be the rainiest region on the globe, Cherrapunji having an average of 424in. a year (the average for July alone being io2in.) while a five-year record at Manoyuram gave an average of 499 inches. It may be remarked that in the western Ghats 546in. fell in one monsoon. The smallest rainfall is found in the north-west, where Jacobabad has an average of only 4in. a year; while part of the Deccan, in the rain-shadow of the Western Ghats, receives less than 20 inches.
The Malay peninsula has a uniformly hot climate, the average temperature being about 8o° F throughout the year, with a daily range of about The rainfall is generally heavy (about iooin.) and is distributed evenly through the year. In Siam and Cambodia the year is divided into a hot rainy summer and a dry winter, which is hot in the south but is :elatively cool in the north. Annam has a considerable rainfall in all months, the largest amounts falling in autumn. The alternation of a north-east mon soon in the winter months with a south-west monsoon in the summer months is found over all this region.
China and Japan.—Under this heading we include the whole of the old Chinese empire from the Pacific to eastern Turki stan, Korea and the whole of Japanese territory from southern Sakhalin to Formosa. This region includes a great variety of climates, from sub-tropical in the south, where the sugar-cane and banana flourish in a mean annual temperature of 72° F, to boreal in the northern interior, with a mean of 36° F and occa sional readings below —3o° F, but the whole area has a regular alternation of two monsoons, the cold dry northerly monsoon of winter and the warm moist southerly monsoon of summer, which is almost everywhere the rainy season. The western and north-western parts of China have an exceedingly continental climate, with a small rainfall and great extremes of temperature, while the sub-tropical islands of Japan are highly oceanic. The main Japanese islands are greatly influenced by two conflicting systems of ocean currents, the warm Kuro Siwo and a cold current which originates in the Sea of Okhotsk. Korea and the east coast of China are for their latitude the coldest parts of the northern hemisphere ; this is due in the first place to the intense cold of winter brought about by the northerly winds and the absence of east-west mountain ranges ; the summers, being very cloudy, are not hot enough to balance the winter cold. Over the interior of China the northerly winds of winter are not so strong, and are warmed by compression during their descent from the northern plateau, while the summers are less cloudy than the coast, hence the interior is generally warmer than the coast throughout the year, especially in the south. Japan has com paratively mild winters on both coasts. The winter climate of the high ground of Tibet is very severe. Spring and autumn are everywhere short, the cold of winter giving place quickly to the heat of summer and vice versa.
The mean annual rainfall varies from less than loin. a year over the Tarim basin, western Tibet and the Gobi desert to nearly 3ooin. in north-east Formosa. Eastern Turkistan is one of the driest regions of the earth. Generally speaking the coast and islands have sufficient rain, the interior of China too little, except in the south-east. The greater part of the rain falls in the period of the south-east monsoon or summer, the only exceptions being coasts which directly face the north-east winds—the east coast of Japan and northern Formosa—but there is an appreciable win ter rain in the Yangtse valley also. Snow falls in winter over almost the whole area. In the coastal regions, especially over south-east Japan, the summer monsoon is the season of typhoons, which do a great deal of damage, not only by the strength of the winds but also by the heavy rainfall and floods which accompany them.
Sclater's Palaearctic region includes Asia, north of the Hima layas and Hindu Kush, and Europe. South-west Asia has a good many animals like those of the Mediterranean lands or those of Africa. East of Sind we enter the Oriental region, which reaches out over shallow sea to Sumatra, Java, Bali and Borneo. The Sunda islands beyond Bali, as far as Timor, and Celebes and the Moluccas are to some extent intermediate between the oriental and the Australian regions. New Guinea may be reckoned with the latter, as the island has a good number of Monotremes and Marsupials, and a pig and a mouse are the only two mammals of higher orders, save the bats. The Moluccas have only two Marsu pials (Cuscus and Belideus) and only the first of these two sur vives in Celebes or in Timor and the eastern Sunda islands. Celebes has an ape, Cynopithecus niger, and the so-called pig deer, Babirusa, which occur in some of the Moluccas as well, but may have been taken thither by man. It also has the pig, a peculiar bull-antelope (Anon), several squirrels, and, on an island off its north coast, the lemuroid Tarsius. Timor has the Cuscus and a shrew as indigenous forms.
Coming west to Java, Borneo and Sumatra, one finds no trace of Australian forms, but oriental types are numerous, though on the whole less so in Java than in the other two, which share with the mainland the Indian elephant, some deer, the tapir and Galeo pithecus (a flying Insectivore peculiar to this region). The chevrotain (Tragulus), the rhinoceros and the Malayan bear occur on the mainland and in Sumatra. The orang-utan and Tarsius inhabit Sumatra and Borneo; the gibbon also occurs in Further India, south China and south Assam, and in Java, but its relative, the siamang, occurs in the Malay and Sumatra. Some monkeys in addition to those named above have reached as far as Java and Borneo. The old-fashioned scaly anteater (Mavis) occurs in all three islands and on the mainland as far west as India, and the same distribution holds good for some lemurs and the Tupaiidae or squirrel-shrews.
These examples, not a complete list for Java, Sumatra or Bor neo, are given to illustrate transitions between the Australian and the oriental fauna, and to show that in the islands of the oriental region one finds several types peculiar to them, some at least of which are old-fashioned forms. One might give at least as interesting a sketch of the reptiles or of the birds, showing that the babbling thrushes are almost absolutely restricted to the oriental region and include peculiar forms in Celebes. The Australian Megapodius, or mound-building bird, extends to the lesser Sunda islands, the Moluccas, Celebes and the Philippines, while a supposedly indigenous form is found on the Nicobar islands. The continental part of the oriental region is especially the home of the hunting leopard and the tiger, but they have spread north and west as well. The rhinoceros and elephant have been mentioned as highly characteristic forms. The analogies between the oriental and the intertropical African fauna (see AFRICA : Fauna) may be followed out with profit. Though south west Asia is in many ways a link between the two, it lacks the anthropoids, lemurs, rhinoceros, elephant, scaly anteater and other forms which might be expected to show that linkage as they occur in both. South-west Asia is also linked with the Medi terranean lands. The lion, the hyena, antelopes and the coney (Hyrax) are African forms that reach into Asia ; though Hyrax does not get in very far, the lion does not go east of the Indian desert, and the hyena avoids the forested parts of India, the antelopes do stretch far into India. Deer, absent from Africa save near the western Mediterranean, are important in Medi terranean lands, south-west Asia and the Palaearctic region.
South-west Asia shares with the Palaearctic region, in which it is often included, asses, antelopes, sheep and goats and the camel, the one-humped form being apparently indigenous in Arabia, while the two-humped or Bactrian camel belongs to the plains farther north. The oxen and buffaloes belong to oriental Palae arctic, south-west Asiatic and African regions, and the antelopes, their relatives, though especially African, also range far north on the open lands of central Asia. The open lands of central Asia, or lands which formerly had similar conditions, are the primary home of the horse, and probably of the two-humped camel, and it seems to be breeds of horse, ox, and sheep from the great steppes and their borders that are most widespread among do mesticated types generally. The yak of Tibet, the musk deer of north-central Asia, the ermine, sable, glutton, reindeer, lemming and lynx of the north are characteristic forms of the Palaearctic region. The mysterious seal and Comephoridae (related to the mackerel) of Lake Baikal should be mentioned as indicating the great changes which have separated that lake from the ocean. Belt long ago suggested that during some phases of the glacial epoch the rivers of Siberia were probably dammed up, giving immense sheets of water between Baikal and the Arctic. Seals also inhabit the Aral and Caspian seas. Eastern Asia yields a few monkeys, penetrating from farther south, a remarkable large carnivore (Aelurus), the raccoon dog (Nyctereutes) and a few special moles, deer, etc. Though some subtropical forms have reached Japan, their numbers are not very large, and this has been held to suggest that continental land connections of Japan have been rather northwards than southwards. The Philippine islands have traces of connections southwards in the presence of Tarsius, Galeopithecus and Tupaia, along with a few more continental mammals, including three deer; it is, however, remarkable that the Philippines seem to lack the gibbon, the rhinoceros, the scaly anteater, etc., which belong to the East Indies. The birds of the Philippines include many forms peculiar to those islands and a number shared with the East Indian islands.
The tiger and leopard (panther) require special mention apart in view of their remarkably wide range ; the former is found over a wide area from farther India to Siberia northward and to the Caspian westward; the leopard is also very widespread and occurs in Africa as well.
Among marine mammals the dugong (Halicore) is found only in the Indian ocean and a dolphin (Platanista) is peculiar to the Ganges, which it ascends for a long distance from the sea.
Among fishes should be named especially the sturgeon, migrat ing up rivers from the Black and Caspian seas, and the related Scaphirliynchus found in the rivers of Aral, of eastern Asia and of the United States of America. (H. J. F.) The vegetation met with over northern Asia much resembles that of the adjacent parts of Europe. The climates are similar and the rainfall, though moderate, is still sufficient to maintain the sup ply of water in the great rivers flowing into the Arctic sea and to support an abundant plant life. A similar affinity exists between the southern parts of Europe and the zone of Asia extending from the Mediterranean across Asia Minor, northern Persia and Af ghanistan to the Himalayas and northern China. The plants and animals along it are found to have a marked similarity in char acter to those of south Europe, with which region the zone is virtually continuous.
The extremely dry and hot tracts forming an almost unbroken desert from Arabia through south Persia and Baluchistan to Sind show a considerable uniformity in the types of life closely ap proaching those of the neighbouring hot and dry regions of Africa. The region of heavy periodical summer rains and high tempera ture which comprises India, the Indo-Chinese peninsula, southern China and the western part of the Malay archipelago, is also marked by much similarity in its plants. The area between south Siberia and the margin of the temperate zone of the Himalaya and north China, including what are commonly called central Asia, Turkistan, Mongolia and western Manchuria, is an almost rain less, high-level region having winters of an extreme severity and summers of intense heat. Its life has a special character suited to the peculiar climatic conditions, more closely allied to the northern Siberian tract than to the other bordering regions. The south eastern parts of the Malay archipelago have much in common with the Australian continent, though their affinities are chiefly In dian. North China and Japan have many forms of life in common and many special forms of China and eastern Asia extend to the Himalayan zone while others clearly indicate a connection with North America.
The foregoing brief review of the principal territorial divisions according to which the forms of life are distributed in Asia, indi cates how close is the dependence of this distribution on climatic conditions, and this will be made more apparent by a somewhat fuller account of the main features of the flora.
The flora of the northern part of Afghanistan approximates to that of the contiguous western Himalaya. Quercus Ilex, the ever green oak of southern Europe, is found in forests as far east as the Sutle j, with other European forms.
In Asia Minor and northern Persia the mountains are clothed, where the rainfall is abundant, with forests of Quercus, Fagus, Ulmus, Acer, Carpinus and Corylus, and various Coniferae. Of these the only genus that is not found on the Himalaya is Fagus. Fruit trees of the plum tribe abound. The cultivated plants are those of southern Europe.
Central Asia.—The vegetation of the dry region of Central Asia is remarkable for the great relative number of Chenopodi aceae,Salicornia and other salt plants being common; Polygonaceae also are abundant, leafless forms being of frequent occurrence, which gives the vegetation a very remarkable aspect. Species of Caragana and other peculiar forms of Leguminosae also prevail, and these, with many of the other plants of the southern and drier regions of Siberia or of the colder regions of the desert tracts of Persia and Afghanistan, extend into Tibet where the extreme drought and the hot sun compensate for the greater elevation, and the summer climate resembles that of the plains farther north. Assemblages of marine plants are frequently met with growing at elevations of 14,000 to i 5,000f t. above the sea in the vicinity of the many salt lakes of central Tibet.
China and Japan.—The flora of north China and Japan is related to that of Siberia and to the neighbouring American con tinent as would be expected from the geographical position. On the other hand there is a close connection between the flora of the Central Provinces of China and the eastern United States of America; the oaks and a number of other genera reach their greatest development in these two countries and have very closely allied species in these parts of the Old and New Worlds respectively. In Hong-Kong and the tropical parts of China some three-fifths of the species are common to the Indian region, and nearly all the remainder are local Chinese forms. The number of species common to southern China, Japan and northern Asia is small. The cultivated plants of China are, with few exceptions, the same as those of India.
The flora of west and south-west China and the bordering parts of south-east Tibet and upper Burma has only recently become well known through extensive botanical exploration. Together with that of the eastern Himalaya with which it is very closely connected, this mountainous area now comprises the richest tem perate flora in the world. A striking feature is the presence of a very large number of species belonging to several genera of alpine plants ; viz., Rhododendron, Primula, Gentiana and Pedicularis, many species being restricted to a very small area. Dwarf species of Rhododendron cover large areas of the moorlands at an alti tude of i 5,000f t. while the high meadow-lands are luxuriant with a very varied vegetation. In Yunnan every attitudinal zone is, represented from tropical jungle to permanent snow. Formosa has largely an endemic flora, but as a remarkable example of dis continuous distribution Taiwania cryptomerioides may be cited. This tree is only known from this island and south-west China.
Indo-Malayan Region.—Recent research has added greatly to the number of plants known to occur in south-eastern Asia. The principal families arranged in order of specific numerical im portance are : Orchidaceae, Leguminosae, Graminaceae, Rubiaceae, Euphorbiaceae, Acanthaceae, Compositae, Cyperaceae, Labiatae and Urticaceae. With the exception of the Compositae and Labia tae these are all more tropical than temperate and but for the temperate and alpine Himalayan species the Compositae would occupy a much lower place still. Within the region, however, there are very great variations, principally under the influence of humid ity and elevation, so that the above order does not hold good for individual subregions. In short we have a somewhat heterogeneous assembly of tropical, temperate and alpine plants, of which, how ever, the tropical are so far dominant as to give their character to the flora viewed as a whole. The Indian flora contains a more general and complete illustration of almost all the chief natural families of all parts of the world than that of any other country.
India and Ceylon.—This subregion contains a by no means homologous vegetation, but presents almost as great a diversity as the region itself. Roughly it may be subdivided into the following zones : Himalayan, characterized by conifers, oaks, rhododendrons, and a number of Compositae. Peninsular, with a large assortment of deciduous trees, including many Leguminosae, that have adapted themselves to the drier conditions, particularly of the genera Butea, Dalbergia, Pterocarpus, Bauhinia, Cassia, Acacia and Albiz zia, as also some genera of other families such as : Cochlospermum, Shorea, Sterculia, Grewia, Terminalia, Gyrocarpus, Euphorbia and Givotia. The teak tree, though not confined to or charac teristic of this subdivision, occurs over widespread areas in the central portion, and in the south the sandal tree appears as an outlier of the genus the focus of which lies in the middle of the Malay islands. The desert zone in the north-west with a small semi-desert zone in the south-east, characterized by a number of xerophytic species belonging to various genera among which may be cited : Capparis, Tamarix, Balanites, Zizyphus, Crotalaria, Prosopis, Acacia and Euphorbia. The humid Malabar zone, which comprises a belt running along the west coast from north Kanara to the extreme south of Travancore and includes the highest hills (8,800ft.) south of the Himalayan chain. The most distinctive feature of this zone, which is akin to the Malayan subregion, is the presence of dense evergreen forests with orders and genera almost absent in the other zones; viz., Guttiferae, Dipterocarpa ceae, Anacardiaceae, Meliaceae, Myrtaceae, Melastomaceae, Am pelidaceae, Piperaceae, Myristicaceae, Araceae and several palms and bamboos; among the shrubs there is a large development of Strobilanthes and other Acanthaceae and Rubiaceae and of Im patiens among the herbaceous plants. The peculiar small plants found clinging to rocks in the stream beds belonging to the family Podostemonaceae occur in considerable number. On the higher hills there are large tracts of open grass lands with an admixture of herbaceous or shrubby Leguminosae, Rubus, Rubiaceae, Com positae, Labiatae and terrestrial orchids and Curcuma. The east ern semi-evergreen zone, which runs parallel with and close to the east coast from Orissa to the south, characterized by species of Acacia, Albizzia, Diospyros, Mimusops and Strychnos, with a con siderable proportion of thorny species. The estuarial or mangrove zone, which occurs intermittently along both coasts of the penin sula as well as along those of all the other subregions.
Ceylon exhibits great affinity with the peninsula and with it some to east Africa. The drier zone lies in the north and the higher ranges of the centre together with the coastal areas of the centre and south correspond more or less with the humid zone in char acter but present a number of endemic forms.
Burma.—The vegetation of Burma links up that of India with the Indo-Chinese and Malayan floras. In the north there is an extension of Himalayan flora, which continues into western China, with a wealth of Rhododendron, Primula, Meconopsis, Quercus and Castanopsis as well as some conifers. Towards central Burma a drier tract is met with and there the plant life is comparable to that of peninsular India, with, however, a larger number of Dip terocarpaceae and a far greater number of species of bamboos. Within this drier zone lies a more or less arid area which does not differ greatly from the desert zone of India. In the southernmost part the vegetation becomes more tropical and more and more akin to the Malayan flora. Here the Anonaceae, Dipterocarpaceae, Guttiferae, Meliaceae, Anacardiaceae, Myrtaceae, Melastomaceae, Myristicaceae, Euphorbiaceae and Orchidaceae abound.
Indo-China.—The knowledge of the flora of this subregion is hardly sufficiently advanced to warrant the framing of a general account. It may be said that as might, indeed, be expected, it cor responds, fairly closely with that of Burma at corresponding lati tudes.
The cultivated plants of the Indo-Malayan region include wheat, barley, rice and maize; various millets, Sorghum, Pennisetum, Panicum, Eleusine; many pulses, peas and beans, mustard and rape ; ginger, turmeric and cardamoms ; pepper and capsicum ; sev eral Cucurbitaceae and brinjal; tobacco, sesamum, poppy, Croto laria and Cannabis; cotton, indigo and sugar; coffee and tea; oranges, lemons of many sorts, pomegranate, mango, custard apple, figs, peaches, vines and bananas. Of late years the Para rubber has also been extensively introduced. The more common cultivated palms are Cocos, Phoenix, Borassus and Areca, which supply coconut, toddy, molasses and betel-nut. Indian agriculture combines the harvest of the tropical and temperate zones.
North of the tropic the winter cold is sufficient to admit of the cultivation of almost all the cereals and vegetables of Europe, wheat being sown in November and reaped early in April. In this same region the summer heat and rain provide a thoroughly tropical climate, in which rice and other tropical cereals are freely raised, being as a rule sown early in July and reaped in September or October. In southern India, and the other parts of Asia and the islands having a similar climate, the difference of the winter and summer half-years is not sufficient to admit of the proper cultivation of wheat or barley. The other cereals may be seen occasionally where artificial irrigation is practised, in all stages of progress at all seasons of the year, though the operations of agri culture are, as a general rule, limited to the rainy months, when alone is the requisite amount of water commonly forthcoming.
Many of the trees of the region produce timber of excellent quality. The teak tree, Tectona grandis, supplies the finest timber, for certain purposes the finest in the world. It is found in greatest perfection in the comparatively humid forests of the west coasts of Burma and the Indian peninsula, where it grows to a height of i soft. or more, mixed with other trees and bamboos. The sal, Shorea robusta, produces a fine, heavy, durable timber, particularly useful for railway sleepers. It is found from the foot of the Himalayas to the Central Provinces and north Madras. The Himalayan cedar, Cedrus Deodara, is the chief timber of that range. Among many other genera yielding excellent timber may be mentioned Dipterocarpus, Hopea, Canarium, Chloroxylon, Gluta, Dalbergia, Pterocarpus, Acrocarpus, Acacia, Terminalia, Diospy ros and Gmelina. The cinchona, from the bark of which quinine is derived, has been introduced and grown with much success in plantations. (C. E. C. F.; C. V. B. M.)