very difficult conditions; yet there are few areas in which the eye will not note some strange vegetable form. In Fig. 3 are illustrated some of the remarkable Mesembryanthemums found in the South African deserts. Here the extremely fleshy leaves, arranged in opposite pairs, produce a sub-globular plant form, a mere mass of watery tissue, which in colour as well as shape appears to mimic the pebbles among which it grows. The frontispiece shows some other types of desert plants. Another difficulty which desert plants have to contend with is this: continual evaporation from off the land of water charged with mineral salts--in some regions in bygone times, in others still following each brief rainy season--has left the soil highly impregnated with substances, of which common salt is one of the most abundant, which, except in very weak solutions, are deleterious to plant life, since water containing them is absorbed with difficulty by the roots. These old lake-bottoms and one-time swamps--such as the alkali deserts of Utah--harbour only a limited number of species specially adapted to their arduous conditions of life. The same difficulty, it may be noted, produces the peculiar and specialized flora of the salt-marshes which fringe the broad bay on which we look down from Farleton Fell. Here there is indeed a superabundance of water, but it is so charged with salt that if even the most vigorous species of the fields or woodlands are transplanted into it they will soon be dead; only plants long inured can grow there. Still, the conditions are not so adverse but that a continuous mat of vegetation extends, growing patchy and dying out only where the surface slopes below high-water mark. There we enter a new domain, where another race of plants, so long inured to salt water that they now cannot exist without it, holds possession.