Our inducement to leave the track was the wish to examine certain solitary trees that we noticed scattered at rather wide intervals on the slopes, nowhere descending below the level of 8,000 feet above the sea, but extending upwards, where they find a resting place, through a vertical zone of about 1,500 feet. The first we were able to reach, which was similar in aspect to the rest, showed a trunk more than two feet in diameter, and about thirty feet high, but broken off and shattered at the top; the branches, with their very dark foliage, diminishing in length upwards, give the whole a conical form. We took it at the time for _Juniperus phœnicea_, which is rather a common tree in the lower valleys. Subsequent examination showed it, however, to differ from that species, and to be identical with _Juniperus thurifera_, a tree hitherto known only in Central Spain, Portugal, and Algeria, and apparently nowhere common. From the number of dead stems seen, it seems to have once girdled this mass of the Atlas with a belt of forest, which has been gradually thinned, and is doomed to ultimate destruction. The existing trees are probably of high antiquity, and their destruction is mainly due to the practice of setting fire to the brushwood to gain pasture for animals; while the young plants, of which not a single one was seen, would be cut off while yet seedlings by the tooth of the goat, the great enemy of tree vegetation—an animal whose disastrous influence, acting indirectly on the climate of wide regions, entitles it to rank as one of the worst enemies of the human race.