The mean temperature of Lamteng (about 50 degrees) is that of the isothermal which passes through Britain in lat. 52 degrees, and east Europe in lat. 48 degrees, cutting the parallel of 45 degrees in Siberia (due north of Lamteng itself), descending to lat. 42 degrees on the east coast of Asia, ascending to lat. 48 degrees on the west of America, and descending to that of New York in the United States. This mean temperature is considerably increased by descending to the bed of the Lachen at 8000 feet, and diminished by ascending Tukcham to 14,000 feet, which gives a range of 6000 feet of elevation, and 20 degrees of mean temperature. But as the climate and vegetation become arctic at 12,000 feet, it will be as well to confine my observations to the flora of 7000 to 10,000 feet; of the mean temperature, namely, between 53 degrees and 43 degrees, the isothermal lines corresponding to which embrace, on the surface of the globe, at the level of the sea, a space varying in different meridians from three to twelve degrees of latitude.* [On the west coast of Europe, where the distance between these isothermal lines is greatest, this belt extends almost from Stockholm and the Shetlands to Paris.] At first sight it appears incredible that such a limited area, buried in the depths of the Himalaya, should present nearly all the types of the flora of the north temperate zone; not only, however, is this the case, but space is also found at Lamteng for the intercalation of types of a Malayan flora, otherwise wholly foreign to the north temperate region. A few examples will show this. Amongst trees the Conifers are conspicuous at Lamteng, and all are of genera typical both of Europe and North America: namely, silver fir, spruce, larch, and juniper, besides the yew: there are also species of birch, alder, ash, apple, oak, willow, cherry, bird-cherry, mountain-ash, thorn, walnut, hazel, maple, poplar, ivy, holly, Andromeda, _Rhamnus._ Of bushes; rose, berberry, bramble, rhododendron, elder, cornel, willow, honeysuckle, currant, _Spiraea, Viburnum, Cotoneaster, Hippophae._ Herbaceous plants* [As an example, the ground about my tent was covered with grasses and sedges, amongst which grew primroses, thistles, speedwell, wild leeks, _Arum, Convallaria, Callitriche, Oxalis, Ranunculus, Potentilla, Orchis, Chaerophyllum, Galium, Paris,_ and _Anagallis_; besides cultivated weeds of shepherd's-purse, dock, mustard, Mithridate cress, radish, turnip, _Thlaspi arvense,_ and _Poa annua._] are far too numerous to be enumerated, as a list would include most of the common genera of European and North American plants.