occurring in Southern Sikkim) was very abundant: its numerous inodorous flowers are pendent, apparent as a protection from the rain; and it is remarkable as being the only species having four petals instead of five. A currant was common, always growing epiphytically on the trunks of large trees. Two or three species of Berberry, a cherry, Andromeda, _Daphne,_ and maple, nearly complete, I think, the list of woody plants. Amongst the herbs were many of great interest, as a rhubarb, and _Aconitum palmatum,_ which yields one of the celebrated "Bikh" poisons.* ["Bikh" is yielded by various _Aconita._ All the Sikkim kinds are called "gniong" by Lepchas and Bhoteeas, who do not distinguish them. The _A. Napellus_ is abundant in the north-west Himalaya, and is perhaps as virulent a Bikh as any species.] Of European genera I found _Thalictrum, Anemone, Fumaria,_ violets, _Stellaria, Hypericum,_ two geraniums, balsams, _Epilobium, Potentilla, Paris_ and _Convallariae,_ one of the latter has verticillate leaves, and its root also called "bikh," is considered a very virulent poison. Still, the absence or rarity at this elevation of several very large natural families,* [_Ranunculaceae, Fumariae, Cruciferae, Alsineae, Geranicae, Leguminosae, Potentilla, Epilobium, Crassulaceae, Saxifrageae, Umbelliferae, Lonicera, Valerianeae, Dipsaceae,_ various genera of _Compositae, Campanulaceae, Lobeliaceae, Gentianeae, Boragineae, Scrophularineae, Primulaceae, Gramineae._] which have numerous representatives at and much below the same level in the inner ranges, and on the outer of the Western Himalaya, indicate a certain peculiarity in Sikkim. On the other hand, certain tropical genera are more abundant in the temperate zone of the Sikkim mountains, and ascend much higher there than in the Western Himalaya: of this fact I have cited conspicuous examples in the palms, plantains, and tree-ferns. This ascent and prevalence of tropical species is due to the humidity and equability of the climate in this temperate zone, and is, perhaps, the direct consequence of these conditions. An application of the same laws accounts for the extension of similar features far beyond the tropical limit in the Southern Ocean, where various natural orders, which do not cross the 30th and 40th parallels of N. latitude, are extended to the 55th of S. latitude, and found in Tasmania, New Zealand, the so-called Antarctic Islands south of that group, and at Cape Horn itself. The rarity of Pines is perhaps the most curious feature in the botany of Tonglo, and on the outer ranges of Sikkim; for, between the level of 2,500 feet (the upper limit of _P. longifolia_) and 10,000 feet (that of the _Taxus_), there is no coniferous tree whatever in Southern Sikkim.