The commencement of the rainy season is the signal in the mountains, as it is very universally throughout India, wherever that season is well marked, for the appearance of a very vigorous and luxuriant growth of plants of annual growth, the seeds (or rootstocks) of which had been lying dormant in the soil awaiting the access of heavy rain. At Simla, as elsewhere in the temperate region of the Himalaya, we find at this season numerous species of Balsams, _Acanthaceæ_, _Orchideæ_, and _Labiatæ_, several Gentians and _Cichoraceæ_, a great many grasses and _Cyperaceæ_, and species of _Parnassia_, _Drosera_, _Pedicularis_, _Roscoea_, _Dipsacus_, _Thalictrum_, _Urtica_, etc., etc. Some of these are quite European genera, while others, as _Roscoea_, are interesting as belonging to orders whose maxima occur in very humid climates. The _Labiatæ_ of the rainy season are mostly species of _Plectranthus_ and _Elsholtzia_, both quite Indian genera, and very extensively distributed in mountainous districts. Balsams are quite an Indian order, and they seem everywhere, as has already been remarked by Dr. Royle and by Dr. Wight, to abound in humid shady places, either in dense forest or on the stony banks of mountain streams, in the drier districts only during the rainy season, but in more humid countries more or less throughout the year. The _Orchideæ_ of Simla are entirely terrestrial, the dryness and cold of the winter months being greater than are compatible with the occurrence of epiphytical species of this natural order, and for the same reason, I presume, _Melastomaceæ_, so abundant in the Eastern Himalaya, are quite wanting.
Among the many advantages of situation by which Simla is characterized, one of the most fortunate is its position on a part of the mountain range which lies transversely to the ordinary direction of the chain, so that the view towards the plains of India, as well as up the Sutlej valley, is very much more extensive than would be obtained, had the station been situated in a less favourable position. This advantage is further enhanced by the sudden rise in elevation of the chain, which enables a resident at Simla to overlook in the direction of the plains the continuation of the range which would otherwise obstruct the view. Towards the interior of the mountains, this advantage is not possessed by Simla; for the ridge of Mahasu, which rises 1000 feet higher than the peak of Jako, obscures at least half of the snowy range, the view being limited in that direction to the course of the valley of the Sutlej, and to the mountains north of that river.