One of this family is edible ('Mesembryanthemum edule'); another possesses a tuberous root, which may be eaten raw; and all are furnished with thick, fleshy leaves, having pores capable of imbibing and retaining moisture from a very dry atmosphere and soil, so that, if a leaf is broken during a period of the greatest drought, it shows abundant circulating sap. The plants of this family are found much farther north, but the great abundance of the grasses prevents them from making any show. There, however, they stand ready to fill up any gap which may occur in the present prevailing vegetation; and should the grasses disappear, animal life would not necessarily be destroyed, because a reserve supply, equivalent to a fresh act of creative power, has been provided.
One of this family, 'M. turbiniforme', is so colored as to blend in well with the hue of the soil and stones around it; and a 'gryllus' of the same color feeds on it. In the case of the insect, the peculiar color is given as compensation for the deficiency of the powers of motion to enable it to elude the notice of birds. The continuation of the species is here the end in view. In the case of the plant the same device is adopted for a sort of double end, viz., perpetuation of the plant by hiding it from animals, with the view that ultimately its extensive appearance will sustain that race.
As this new vegetation is better adapted for sheep and goats in a dry country than grass, the Boers supplant the latter by imitating the process by which graminivorous antelopes have so abundantly disseminated the seed of grasses. A few wagon-loads of mesembryanthemum plants, in seed, are brought to a farm covered with a scanty crop of coarse grass, and placed on a spot to which the sheep have access in the evenings. As they eat a little every night, the seeds are dropped over the grazing grounds in this simple way, with a regularity which could not be matched except at the cost of an immense amount of labor. The place becomes in the course of a few years a sheep-farm, as these animals thrive on such herbage. As already mentioned, some plants of this family are furnished with an additional contrivance for withstanding droughts, viz., oblong tubers, which, buried deep enough beneath the soil for complete protection from the scorching sun, serve as reservoirs of sap and nutriment during those rainless periods which recur perpetually in even the most favored spots of Africa. I have adverted to this peculiarity as often seen in the vegetation of the Desert; and, though rather out of place, it may be well--while noticing a clever imitation of one process in nature by the Cape farmers--to suggest another for their consideration. The country beyond south lat. 18 Deg. abounds in three varieties of grape-bearing vines, and one of these is furnished with oblong tubers every three or four inches along the horizontal root. They resemble closely those of the asparagus. This increase of power to withstand the effects of climate might prove of value in the more arid parts of the Cape colony, grapes being well known to be an excellent restorative in the debility produced by heat: by ingrafting, or by some of those curious manipulations which we read of in books on gardening, a variety might be secured better adapted to the country than the foreign vines at present cultivated. The Americans find that some of their native vines yield wines superior to those made from the very best imported vines from France and Portugal. What a boon a vine of the sort contemplated would have been to a Rhenish missionary I met at a part in the west of the colony called Ebenezer, whose children had never seen flowers, though old enough to talk about them!