On Saturday morning we came to the bank of the Ikòpa, which river is at some points half-a-mile or more wide, but then at its lowest level, being apparently very shallow, but so interrupted everywhere with shelves of rock that it would be difficult for even a small canoe to make its way far. There were numerous islands, covered with bamboo, bàraràta, _rofìa_-palms and other vegetation. From a low hill we had a view over an immense expanse of flat country on the western side of the river. Only here and there was the level broken by a line of hills of small elevation. After leaving the Ikòpa we found ourselves in a very different kind of country from any we had yet passed through, a succession of low hills or mamelons of dry sandy gravel, with hardly any vegetation, and looking as if no rain had fallen upon it for years. In the afternoon I noticed that a large number of granite boulders were strewn over the country, and could hardly doubt that these, from their rounded forms, but especially from the absence, as far as I could see, of any such rock _in situ_, must by some means or other have been transported from the granitic region of the interior far to the eastward. Must this not have been glacier or iceberg action? Although it is difficult to understand such agency in the tropics. Ten years after making the journey, my friend, Mr Baron, in travelling across the island towards the north-west coast, but about a hundred and twenty miles farther north, came across isolated rocks, which were quite different in composition from anything near them. Of these he said: “I could think of no agent to account for their occurrence but that of glacial action. They seemed to me to be perched blocks, as there was no hill near from which they could have fallen, nor any rock of the kind _in situ_.” I was interested to find that an expert in Madagascar geology like Mr Baron had come to the same conclusion as myself with regard to these granite boulders. Early in the afternoon we arrived at Mèvatanàna, the most important place in this part of the country, with about a hundred houses; it had, however, been quite recently burnt down, but was in process of rebuilding. The houses seemed rather larger than those in Imèrina, made of round-pole framework, filled in with _bàraràta_ stems, the roofs of _rofìa_-palm leaf-stalks and thatched with grass. We secured a new house, not quite finished; and as this was very like a large birdcage, besides having no doors in the three doorways, we put up the tent on one side, piled up our heavy luggage against another of the doorways, and hung a rug over the third, so as to make ourselves less of a public spectacle.