Shortly after leaving Oeiras, we began to be much tormented by a species of tick, to which the Brazilians give the name of carrapato. These insects abound in dry bushy places, where they attach themselves to the slender twigs; at first they are very small (carrapatos miudos), and may be seen in clusters consisting of many hundreds; these as soon as any animal passes by and touches them, instantly adhere to it, burying their suckers so deeply into its skin, that it is only by using considerable force they can be withdrawn. If not taken off they go on increasing in bulk till they become as large, and even larger, than a common horse-bean; they even increase in size on the grass and bushes, but then have a lean flat appearance; it is to this form that the name carrapato grande is given. Spix and Martius believe the large and small kinds to be distinct species, but I think there can be no doubt that they are the same insects in different stages; St. Hilare is of this opinion, and so are the inhabitants themselves. It is only in the beginning of the dry season that the small carrapato is to be found in those districts which are infested by them, but as the season advances, they gradually disappear, to be replaced by the larger ones. They attach themselves indiscriminately to all kinds of quadrupeds, but the horse and the ox suffer most from their attacks, and in very dry seasons they exist in such numbers, that whole herds of cattle perish from the exhaustion which they produce. If, however, the animal on which they live can hold out till the rains set in, it soon regains its strength, as wet is very fatal to the carrapato; I have frequently seen some of my horses that were infested by these creatures, get nearly free from them after swimming across a broad river. Some horses I found were much more subject to them than others. We found the dry bushy country above Parnaguá swarming with these pests, and almost every night, we had to pick hundreds of them off our bodies before we could turn into our hammocks. The men suffered more than either Mr. Walker or myself, as they were on foot, and their legs were bare from the knees downwards. When I walked out to botanize in the neighbourhood of the places where we encamped, I used generally to get completely covered with them, and had to change my dress, but by laying the infested articles in the bright sun-shine for a quarter of an hour they became fit to put on again. A favourite little ring-tailed monkey, which I obtained from an old Indian some days after we left Oeiras, also used to suffer very much from these insects. When full grown, a large carrapato very much resembles the ripe seed of the castor oil tree. In dragging off very large ones, the wound which is left often becomes a very bad sore. The carrapato belongs to the genus _Ixodes_, of Latreille.