The most remarkable feature of the flora of this region, is, undoubtedly, the very large proportion of common plants of the colder temperate region (Central and North-Western Europe), here found associated with species of very different type. Nearly one-half (70 out of 151) of the species found in the upper zone, belong to this category, and the proportion is here actually larger than it is in the higher mountains of Southern Spain. It was further remarkable that several of these northern species, such as the wild gooseberry, are plants that do not extend to the South of Spain, although climatal conditions must be at least equally favourable, and whose nearest known habitat is six or seven hundred miles distant. Especially to be noted was the fact that, with the doubtful exception of _Sagina Linnæi_ (the _Spergula saginoides_ of the older botanists), not one of the plants in question is characteristically an Alpine species, or typical of the Arctic or glacial flora. Combining this with the almost complete absence of rushes and sedges, we are forced to conclude that, whatever agencies may have contributed to make up the existing flora of the Great Atlas, transport by floating ice during the last glacial period cannot have been amongst them. If such ice-rafts were ever borne to what was then probably a long western peninsula of Northern Africa, they must either have foundered at sea with all their vegetable crew, or, if cast ashore, must have found an inhospitable region where the voyagers were starved, and left no descendants. As was to be expected, from the habitual dryness of the climate, ferns were here deficient in number and variety. In the upper region we found very sparingly six of the common species of Northern Europe; and lower down, in the middle part of the valley, we were able to add to our lists but two southern forms. About one-third only of the species found in the upper-region could be described as properly belonging to the Mediterranean flora; most of these being widely-spread plants, while a few are exclusively confined to the nearest neighbouring mountain regions—the Lesser Atlas of Algeria or the mountains of Southern Spain. But there was little in the general aspect of the vegetation to suggest any special connection with either; and several of the conspicuous plants have been hitherto known only in very distant regions. A bright-flowered _Veronica_ appeared to be no more than a large variety of a species peculiar to Asia Minor; _Medicago suffruticosa_ had hitherto been seen only in the Pyrenees; and _Evax Heldreichii_ had been detected nowhere nearer than the mountains of Sicily and Eastern Algeria. Our original expectation of finding some connecting links between the special flora of the Canary Islands and that of North Africa was so far completely negatived, and we saw nothing to suggest their existence.