Shortly before we reached the descent of the Serra, the great variety of new plants which I found growing there, caused me to linger far behind the troop, but as this was very frequently the case, the men took no notice of it. I did not often keep one of them with me, as my eye, from long practice, had become well acquainted with the track of the troop, from the appearance of the horses’ and the men’s foot-marks; and here, moreover, the road had been so long free from travellers, that there seemed no chance of any mistake occurring. In this, however, I was deceived, for although I traced them to the lower part of the upper lake, where the ground was very soft, and much trodden by the cattle and horses that came there to drink; beyond this muddy tract, which was of considerable size, I could not trace the foot-marks of my troop, although I spent a long time in trying to do so. It is well understood among travellers in these desert parts of Brazil, that if one of the party should by any chance remain behind, and be unable to find the track of his companions, he is to remain in the neighbourhood of the spot where he first lost it, so that he may the more readily be found by those who return to look for him. Acting upon this, and feeling certain that before night some one of my party would be sent in search of me, I returned to the foot of the Serra, and, under some shady trees by the road-side, dismounted, and tying the fore-legs of my horse with the bridle, so that he might feed, and not stray, I sat down under one of the trees to study attentively the plants which I had collected during my morning’s ride. My only fear was lest any of the wandering tribes of Indians, who were known to be in the neighbouring woods, should happen to come across me, for in consequence of the persecution they have received from the Brazilians, they consider every white man they encounter lawful game to shoot at and destroy. It was not till late in the afternoon that Mr. Walker, finding I did not make my appearance, sent one of the men to look for me; and when we returned to the place where I had been unable to follow the track, I found they had passed over to the other side of the lake by a very narrow path, which was completely covered over with long grass.