362 ILLUSTRATIONS OF THE BOTANY OF [ Orchidew. 
7,000, 8,000, and 9,000 feet, in the Andes of Quito and Granada; while Oncidium 
nubigenum, occurs as high as at 14,000 feet in the Andes of Peru. So I found 
Dendrobium alpestre, at 7,000, and Celogyne precov at 7,500 feet of elevation on 
the Oaks of Mussooree and Lundour in 30° of N. latitude. fae 
From this extensive: distribution, it would ‘appear that there was not the same 
connexion between structure and climate as we have seen to exist in most other 
families. But this may be an apparent, rather than a real exception. Many of the 
Orchide@ being provided with tuberous roots, have these, from their under-ground 
situation, protected from the vicissitudes of temperature, and as they often exist in 
moist situations, and flourish during the summer temperature, a kind of local climate 
may be supposed to be produced, in which a less degree of temperature appears to be 
necessary. Thus, on the mountains of hot countries, there is constant humidity in 
the rainy season, “from the air charged with moisture in the heated valleys rising 
and depositing it on the mountains, when it reaches an elevation where it is cooled 
”? 
beyond the point of saturation ; and this being accompanied with equability, we have 
two of the characteristics of a tropical climate, and find a lower degree of tempera- 
ture, fully sufficient for the most luxuriant growth of many tropical genera and families 
of plants, with numerous terrestrial, and the above-named epiphytal Orchidee. 
This is the characteristic of the Andes, in what Humboldt has) called <*'the region 
of clouds ;” so, in the Himalayas, at 7,000 and 8,000 feet, the thermometer ranges 
between 60° and 70° for nearly three months, in the same place where in winter it 
falls below the freezing point, and snow -lies on the ground for a week together. It is 
worthy of i inquiry; whether the equability of temperature, a little higher in the air, 
is not greater even than it is on the mountain-top, and whether even the vicissitudes 
of temperature are not less detrimental, because occurring in a very rarified medium. 
It might be expected, therefore, from the more northern situation, that the Orchidee 
in the author’s collection, would be in less proportional numbers. This is certainly the fact, 
but more so than is actually the case, because the author was prevented by his medical 
duties from travelling as much as was necessary, for the discovery of plants not widely 
diffused ; while the native plant-collectors had not sufficient zeal to expose themselves 
much in the rainy season. The species are not more than eighty in number, and the. 
majority from the neighbourhood of Mussooree. The two most remarkable plants in 
the collection, Dr. Lindley considers to be a Corallorhiza with leaves, and a new 
species of Neottia, allied to our European bird’s-nest. Dr. Falconer, my friend and 
_ successor in the charge of the Saharunpore Botanic Garden, being required to seek for 
localities for the cultivation of tea, has fortunately had much greater opportunities of 
travelling. He has succeeded in making many important accessions to the family of 
Orchidee, as his untiring zeal induced him to travel much in the midst of the rainy 
season, to the great risk not only of his health but of his life. He informs me that 
he has discovered a new genus of ‘the Gastrodieg, and another of the Malavidee, of 
which the plant stands nine feet high, and makes a most splendid appearance, 
with 
