I have attempted elsewhere[45] to give a sketch of the views which I hold as to the probable origin of the chief types of phanerogamous vegetation. I there pointed out that, at a period when physical conditions in the lower regions of the earth’s surface were widely different, and the proportion of carbonic acid gas present in the atmosphere was very much greater than it has been since the deposition of the coal measures, it was only in the higher region of great mountain countries that conditions prevailed at all similar to those now existing. I further argued that, if the early types of flowering plants were confined, as I believe they were, to the high mountains, we could not expect to find their remains in deposits formed in shallow lakes and estuaries until after the probably long period during which they were gradually modified to adapt them to altered physical conditions.

VALLEY OF THE PARAHYBA.

A general survey of the South American flora shows, along with elements derived from distant regions, a large number of types either absolutely peculiar to that continent, or which, in some cases, appear to have spread from that centre to other areas. Of these peculiar types some may probably have originated in the Andean chain, but as to the majority, it seems far more probable that their primitive home was in Brazil; and it is precisely on the ancient mountains of this region that I should look for the ancestors of many forms of vegetation which have stamped their character on the vegetation of the continent.

I should be the first to admit that the views here expressed have no claim to rank as more than probable conjectures; but I hold that these, when resting on some positive basis of facts, are often serviceable to the progress of science, by stimulating inquiry and leading observers to co-ordinate facts whose connection had not previously been apparent.

In following the valley, in places where the siliceous soil supported only a scanty vegetation, I was struck by the singular appearance of scattered piles, usually about four feet in height, having much the appearance of rude milestones, occurring here and there in some abundance, but never very near each other. I was often able to avail myself of the short halts of the train at wayside stations to secure specimens of interesting plants, but I was not able to approach near to these unknown objects. I have no doubt, however, that they were habitations of termites, or, as they are commonly called, white ants. I have never been able to conjecture the origin of the instinct that induces so many species of termites in different parts of the world to construct dwellings in this form, nor what advantage they can derive from it.

As the Parahyba appeared to be a rapid-flowing stream, it is probable that in following the valley the railway descends considerably before it reaches the point, about eighty miles north of Rio, where it abruptly turns away from the river to make its way to the capital. The appearance of the vegetation announced a change of climate, but I did not notice any palms by the way. The country between the Parahyba valley and the coast appears to be an irregular mountain tract, nowhere of any great height, with projecting summits rising here and there of the same general character as those already described, and the railway follows a sinuous course so as to select the lowest depressions between the neighbouring bosses of granite. As we wound to and fro, constantly changing our direction amid scenes of increasing loveliness, night closed with that suddenness to which one becomes accustomed in the tropics, and the last part of the way was unfortunately passed in darkness. The approach to Rio must be surpassingly beautiful, but, beyond the fantastic outlines of the surrounding mountains, little could be discerned save the lights of the city, visible for many miles before we reached the railway station.

After a long drive through paved streets, I reached the English hotel (Carson’s), and was curtly informed that the house was full. The next in rank is the Fonda dos Estrangeiros, to which I proceeded, and found quarters in a rather shabby room, not overclean. The general style of the establishment and the food provided answered the same description. It is generally admitted that the accommodation for strangers in the capital of Brazil does not come up to the reasonable expectations of travellers.

THE BAY OF RIO JANEIRO.

By quitting the steamer at Santos, and travelling to Rio by land, I had gained some slight acquaintance with a new region, but I was well aware that I had suffered a considerable loss. The view on first entering the Bay of Rio Janeiro is one of those spectacles that leave an ineffaceable impression even on persons not very sensitive to natural beauty, and one on which my fancy from early youth onwards had most often dwelt. The pursuits of a naturalist, besides their own fascination, offer additional rewards to all who worship in the temple of Nature, but they also sometimes exact a sacrifice. Sallying forth on the morning of July 8, a little under the impression of the unattractive quarters of the night, I had but very moderate expectations as to what might be enjoyed of the scenery in the midst of a large city and its surroundings, but I was speedily disabused. Man has certainly done little to set off the unequalled fascinations of the place, but he has been powerless to conceal them. I passed a delightful day, partly strolling much at random on foot, and occasionally availing myself of the street-cars, which are frequented by all classes, and afford a stranger the best opportunity for seeing something of the very mixed population.