and ascertained it to be _Cattleya labiata_. Those on the Gavea will long continue to vegetate, far from the reach of the greedy collector. The road, after winding round the Gavea, terminates at a small salt water lake, which passengers, who follow this route, are obliged to cross, or rather to pass from one end to the other, in consequence of the flank of a high hill which runs into it, and prevents a passage along its margin. We passed the lake in a rotten leaky canoe, and saw on the face of the steep rocks many curious plants which we could not reach. The path which led to the house where we were to take up our quarters, lay for about two miles through a flat meadow-land, partly in its original state, and partly planted with Indian corn, Mandiocca, and Bananas. We passed many small habitations belonging to poor people of colour, mostly fishermen. Before reaching the foot of the mountain over which the road leads to Tijuca, we passed a migrating body of small black ants. The immense number of individuals comprising it may be imagined from the fact, that the column was more than six feet broad, and extended in length to upwards of thirty yards. The ground was completely covered with the little creatures, so closely were they packed together. The natural history of ants has as yet been but little studied, particularly with regard to the enumeration of species. They are more numerous than naturalists are aware of. In those parts within the tropics where humidity prevails, they are neither so varied in species, nor so abundant in individuals, as in drier districts. While residing at Pernambuco, I remember taking notice of all the species I met with in the course of a single day, and they amounted to about twenty-five. Before ascending the hill we visited the falls of Tijuca, which are only at a short distance from the road. The crystal water of a large rivulet falls over two successive gently inclined masses of rock, upwards of one hundred feet high. It rather glides in a broad broken sheet than falls, and is received in a large pool below. This cascade reminded me of those which are so often to be met with in the wooded glens of Scotland. By dusk, after gradually ascending the mountains, we reached the house; it is situated in an old coffee plantation, belonging to a Brazilian nobleman, but it was then rented by a party of young English merchants in Rio, who used it as a holiday resort, and, by the kindness of one of them, we were allowed to remain at it for a few days.