of moisture from the outer to the inner Himalaya, Quercus incana and Rhododendron arboreum being characteristic of the outer, and Pinus Gerardiana (which commences to appear on the north side of Wangtu on the Hindustan-Tibet Road, for instance) and Ephedra, of the inner mountains. West of the Ravi the change from the outer flora type to that of the inner is more rapid, owing to the lesser rainfall, the Quercus incana, etc., being only found on the outermost range. In the more elevated temperate areas trees and shrubs of European genera and species occur, such as yew, juniper, walnut, box, ivy and mistletoe.

Four conifers are particularly characteristic of the region, viz. Deodar (Cedrus deodara), P. Gerardiana, the Cypress (C. torulosa) and the Juniper (J. communis). These only extend eastwards for a short distance into Nepal and the Eastern Himalaya. The deodar does not extend eastwards of the west of Nepal; its habitat is from 4000 feet (in the Punjab) up to 10,000 feet, and it is found even higher. In Kumaun its minimum elevation is about 7000 feet. Gamble describes the distribution of the deodar as follows:

"The deodar is a gregarious tree forming fine forests in the valleys of the Punjab and Kashmir, as well as in those of the Tons, Jumna and Bhagirathi, ending up in the watershed of the Alaknanda. The forests are rarely of pure deodar, though exceptions are met with occasionally and usually in the form of sacred groves; but more commonly the deodar is associated with the spruce and blue pine and the three oaks, Kharshu, moru and ban, in their various zones. Sometimes the silver fir (Abies Pindrow) accompanies it, but more rarely; the cypress in its favourite localities joins it; and the yew is often found under it, and at low elevations it mixes with the long-leaved pine (P. longifolia)." A variety of other broadleaved trees are also found associated with it.

The deodar has for long formed one of the most valuable timbers of the region, and the accessible forests were heavily cut before systematic forest conservation was introduced into Northern India. The Pinus Gerardiana, with a beautiful silvery bark, is a native of Afghanistan and of the drier valleys of the Himalaya as far east as the Sutlej. Cupressus torulosa is more sparingly distributed throughout the region, being usually found in clumps and patches on precipitous limestone rocks. The juniper is found in all the drier parts of the mountains from Afghanistan to Kumaun.

As has been said the outer hills up to about 3000 feet, or even higher, are occupied by a forest similar in character to that of the deciduous forest zone, the type found in the neighbouring Dun and Siwaliks. The sâl is the principal species of this forest, accompanied by Terminalia tomentosa and Chebula, Adina cordifolia, Anogeissus latifolia and Ougeinia dalbergioides; whilst Dalbergia Sissoo and Acacia Catechu occupy the silt deposits on the riverain terraces and banks and on the islands in the beds of the rivers, the latter species being also found scattered on the hill-sides. Pinus longifolia makes its appearance, at first singly or in clumps, in the upper elevations of the sâl, Buchanania latifolia, Bauhinias, Ougeinia dalbergioides, etc., forest. Higher up it appears in compact blocks, and where the sâl belt is left behind it forms extensive, often pure, forests on the hot and often stony hill-sides. When in mixture the species occurring are Boehmeria rugulosa, Bauhinia retusa, Engelhardtia Colebrookiana and species of Ficus. Above this, between 4000 and 6000 feet, a vegetation characteristic of temperate regions clothes the mountains. The commonest trees are Quercus incana, Rhododendron arboreum and Pieris ovalifolia; all of these occur throughout the Western Himalaya; but to the westward they are restricted within gradually narrower limits, and in the extreme west are found only in moist and shady localities, whereas in Kumaun and Garhwal they are most abundant on the drier and hotter slopes. None of these species occur in Kashmir. In the valleys and ravines the forest is usually very different, containing such species as Quercus glauca, Celtis, Alnus, Esculus, Populus ciliata, Ulmus Wallichiana, Betula alnoides, Carpinus viminea, several maples and others. Between 6000 and 8000 feet is the chief zone of the deodar and the blue pine, as well as of the cypress; whilst above 7000 feet Quercus dilatata (moru) generally supersedes Quercus incana (ban), and small box (Buxus sempervirens) forests occur in damp valleys, especially on limestone. Between 8000 and 11,000 feet the principal trees are the Himalayan Spruce (Picea morinda), the Himalayan Silver Firs (Abies webbiana and A. Pindrow), the former from 10-14,000 feet, the latter from 7-9000 feet or a little above, and a third Oak, the Kharshu (Quercus semecarpifolia); whilst small Bamboos, with numerous Strobilanthes and Balsams, are conspicuous features of the undergrowth. One of the last trees met with on ascending to 12,000 feet is a Birch (Betula utilis), accompanied by a tangled

undergrowth of a straggling shrubby Rhododendron (Rhododendron Anthopogon). Above this again is the Juniper, whilst close to the snow-line all trees and shrubs have disappeared, their places being occupied by numerous Alpine plants, such as gentians and primroses, with mosses and other cryptogams. (2) The Alpine Forests of the Afghanistan and Baluchistan Region. The characteristics of the Western Himalayan forests persist in this region as far south as the Kurram Valley. The conifers consist of the Deodar, Pinus Gerardiana, the Blue Pine (Pinus excelsa), the Spruce, Silver Fir and Juniperus excelsa; the Oaks are restricted to Q. ilex and semecarpifolia, occurring with Prunus Padus and a species of Rhus. At the upper elevations the birch is replaced by thickets of dwarfed Juniperus communis. The undergrowth consists of Rhododendron campanulatum, Viburnum, Syringa Emodi and persica, Cratagus Oxyacantha, Cotoneaster bacillaris, wild roses and species of Ribes, etc. South of the Kurram the forest becomes poorer in character, filling high side valleys, the outer hills becoming more and more barren until Baluchistan is reached. The chief trees of Baluchistan proper with the tributaries of the Harnai and the Bolan are the Juniperus macropoda, which forms forests, and the olive, which is seen dotted over the barren hills. In favourable situations clumps or isolated individuals of the following are found: Pistacia Khinjuk, Berberis, Fraxinus xanthoxyloides and Crataegus Oxyacantha. In North Zhob the Pinus Gerardiana appears in small blocks of forest, as at Shinghar, Spiraghar, etc., areas which the author has personally visited. In this region the tribesmen attach a high value to the edible seed of this pine which they collect and sell.

(3) The Alpine Forests of the Eastern Himalayan Region. The higher forests of this region consist of the conifers, Silver Fir, Abies Webbiana, the Spruce, Larch (Larix Griffithii), which is only found in the inner ranges, Juniperus recurva and the Hemlock Spruce (Tsuga Brunoniana). According to Duthie the hemlock spruce extends as far west as the Kali Valley in Kumaun, and Webber mentions it in his exploration of the forests of Kumaun in 1864. In British Sikkim, in the Eastern Himalayan Region, Gamble says it is found in the Siri Valley (and the Author saw it himself when in charge of the Tista Division in this region), where it grows mixed with or just below the silver fir and associated with yew, oaks, especially Q. pachyphylla, rhododendrons (chiefly R. grande, Falconeri and barbatum) and the Maling bamboo (Arundinaria

racemosa). It is a fine tree growing to as much as 120 feet in height, with a stately blunt pyramidal crown with branches spreading like the cedar, but drooping gracefully on all sides. It grows up at about 10,000 feet. Below the conifers come the rhododendrons, which form gregarious forests, the two tree species being R. arboreum and R. grande. The other rhododendrons are small trees or epiphytic shrubs, such as R. Dalhousie, Edgeworthii, and the species already mentioned above. Associated with the rhododendrons are Pieris ovalifolia, Buddleia Colvillei, Hydrangea altissima and birches and maples. The oaks and chestnuts begin to appear at the lower elevations occupied by the rhododendrons (8000 feet being about their minimum elevation) and occupy a belt of roughly between 6000 and 8000 feet. The Oaks consist chiefly of Q. lamellosa, and glauca and the Chestnut (Castanopsis Hystrix); lower down Magnolias, such as Magnolia Campbellii and others, Michelia excelsa, lanuginosa and Cathcartii, with large maples, laurels and species of Echinocarpus, Bucklandia, Elaeocarpus, Machilus, Phæbe and Nyssa and several species of small bamboos, tree ferns and canes are met with; also climbers, such as Thunbergia and others. conspicuous owing to their bright-coloured flowers. Still lower the forest changes, large trees of Cedrela, Terminalia, Duabanga, Canarium, etc., making their appearance with palms of the genera Caryota, Livistona, Phoenix, Didymosperma and the large screw pine, Pandanus furcatus. This type drops down into the sâl forest with its associated species, which is characteristic of the deciduous forest zone. The Tista and Rungeet Valleys exhibit the character of this zone as it appears in the foot-hills of the Eastern Himalaya à merveille, and shows the differences existing in the zone due to the heavier rainfall and damper heat of the eastern foothills.

(4) The Alpine Forests of Burma Region. The Burmese tropical evergreen forests give place at elevations of from 3000 to 3500 feet to trees more characteristic of temperate climates, the development owing to the dampness being very great. Oaks, Chestnuts (Castanopsis tribuloides), with other cupuliferous species, Ternstroemia japonica, Bucklandia populnea, species of Eugenia, with temperate Laurineæ, Ostodes paniculata, Podocarpus, etc. Perhaps the most distinctive feature of the region are the pines. At the higher levels they form either pure or nearly pure forests, whilst

lower down they are mixed with broad-leaved species such as Eng. The chief pine is the Pinus Khasya, which occupies the hilly parts of Upper Ava and Martaban. In Upper Tenasserim a second pine appears growing at a lower elevation, the Pinus Merkusii, occurring chiefly on the sandstone hills of the Thaungyin in Upper Tenasserim.

E. THE RIPARIAN FOREST ZONE

The types of forest found in this zone are almost invariably different from those of the surrounding forests, although they often present similar characteristics to the forests of the moister regions. The riparian forests owe their special attributes to the water the areas they occupy receive from the periodical overflow of rivers, or to direct percolation from rivers or considerable sheets of inland waters. The forest vegetation resulting is usually different from that existing on adjacent areas beyond the reach of this overflow water. The individual areas occupied by this vegetation are not necessarily of great extent, but collectively they form a not inconsiderable part of the forest area of India. The character of this riparian forest varies according to its geographical position, but two main types of this class of forest may be given as characteristic of the zone: the first, the forests of the Lower Indus in the Sind desert; the second, the swamp forests of Burma.

The riparian forests in the rainless tracts of Sind are represented by mere fringes of tree vegetation on the river banks, where the rise of the Indus causes the inundation of large riparian areas during the hottest months. Large, valuable and quick-growing Acacia arabica forests are the result of these inundations, covering extensive areas of the low-lying alluvium. Tamarix gallica forests fringe the banks of all permanent rivers in the Sind-Punjab zone, interspersed with Populus euphratica, Dalbergia Sissoo and Acacia arabica which, even when no inundations take place, are nourished by perennial percolation from the streams. These areas are in the northwest of India known as " sailaba," and are easy of afforestation in spite of the high grasses (Saccharum Sara and Munja) which frequently cover them.

The forest trees which are found to disappear as the banks of the stream are left, are the Dalbergia Sissoo and Poplar. Acacia arabica follows next and Tamarix dioica takes the place