THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, August 3 , 1358. 
sequently, tell on the health of the inmates, so as more than 
to do away with the advantages named. Do you, or any of 
your readers, heartily approve of cement,—not theoretically, 
hut from actual experience ? 
As to covers for beehives, the straw sheaf, no doubt, 
possesses the valuable advantage of coolness in summer 
and warmth in winter, but then it has the disadvantage of 
being a receptacle for moths and mice. I found more than 
one of the latter snugly ensconced in my sheaves this last 
spring, although the hives are placed on single posts. It is, 
besides, a clumsy affair to handle and replace neatly, causes 
an abominable litter among flowers, and requires to be 
frequently renewed to have anything of a clean look. Could 
you, or any of your readers, inform me of a substitute equally 
efficacious for the purpose ? The discoverer of such would 
j confer a lasting benefit on bee-keepers. 
I have thought of a thick wooden cover, well painted, and, 
what would be better, perhaps, of wood not so thick, but 
double; the space—about an inch or so—between the boards 
to be filled with sawdust, which would cause it to be im- 
| pervious to the sun’s heat. It could be attached firmly to 
the board, and divided into two parts ; the back one, hinged 
as a door for inspection, or removal of the hives, brought 
in neatly to a point at the top, on which could be placed a 
i little turned ornament, finished as the taste or means of 
the proprietor would allow. A nice thing of this sort might 
be placed with effect in some corner of the flower garden. I 
mean to try an octagon cover of this fashion for a set of 
Stewarton boxes, but would it be too close ?—A Scotch 
Bee-keeper. 
[If the plan adopted by “ Tyro,” detailed at pp. 208 and 
238, is found to answer generally, then the old straw bee- 
skip may be preferred to any. We never use straw covers. 
Over our Marriott’s and Neighbour’s hive, we have little 
wooden houses, very much after the form of those in boxes 
of Dutch toys. Over flat-topped hives, such as the Stewarton 
and Tegetmeier’s, we turn a brown earthenware milk-pan, 
large enough to project two or three inches all round. These 
pans are painted green, and the hives stone-colour. We 
believe bees rarely suffer from cold.— Ed.] 
PLANTS IN THE KALAHARI DESERT- 
CENTRAL AFRICA. 
The quantity of grass which grows in this remarkable 
region is astonishing, even to those who are familiar with 
India. It ususally rises in tufts with bare spaces between, or 
the intervals are occupied by creeping plants, which, having 
their roots buried far beneath the soil, feel little the effects of 
the scorching sun. The number of these which have tuberous 
roots is very great; and their structure is intended to supply 
nutriment and moisture when, during the long droughts, they 
can be obtained nowhere else. Here we have an example of 
a plant, not generally tuber-bearing, becoming so under cir¬ 
cumstances where that appendage is necessary to act as a 
reservoir for preserving its life; and the same thing occurs 
in Angola to a species of Grape-bearing Vine, which is so 
furnished for the same purpose. The plant to which I at 
present refer is one of the Cucurbitacese, which bears a small, 
scarlet-coloured, eatable Cucumber. Another plant, named 
Leroshua, is a blessing to the inhabitants of the Desert. We 
see a small plant with linear leaves, and a stalk not thicker 
than a crow’s quill; on digging down a foot or eighteen 
j inches beneath, we come to a tuber, often as large as the 
head of a yo\mg child; when the rind is removed, w T e find it 
to be a mass of cellular tissue, filled with fluid much like that 
in a young Turnip. Owing to the depth beneath the soil at 
which it is found, it is generally deliciously cool and refreshing. 
Another kind, named Mokuri, is seen in other parts of the 
country, where long-continued heat parches the soil. This plant 
is a herbaceous creeper, and deposits underground a number of 
tubers, some as large as a man’s head, at spots in a circle a 
yard or more, horizontally, from the stem. The natives strike 
the ground on the circumference of the circle with stones, till, 
by hearing a difference of sound, they know the water-bearing 
tuber to be underneath. They then dig down a foot or so, 
and find it. 
But the most surprising plant of the Desert is the ct Kengwe, 
2S1 
or Kerne” (Cucumis coffer), the Water Melon. In years 
when more than the usual quantity of rain falls, vast tracts of 
the country are literally covered with these Melons; this 
was the case annually when the fall of rain was greater than 
it is now, and the Bakwains sent trading parties every year 
to the lake. It happens commonly once every ten or eleven 
years, and for the last three times its occurrence has coincided 
with an extraordinarily wet season. Then animals of every 
sort and name, including man, rejoice in the rich supply. 
The elephant, true lord of the forest, revels in this fruit, and 
so do the different species of rhinoceros, although naturally so 
diverse in their choice of pasture. The various kinds of ante¬ 
lopes feed on them with equal avidity, and lions, hyamas, 
jackals, and mice, all seem to know and appreciate the com¬ 
mon blessing. These Melons are not, however, all of them 
eatable; some are sweet, and others so bitter, that the whole 
are named by the Boers the “ Bitter Water Melon.” The 
natives select them by striking one Melon after another with 
a hatchet, and applying the tongue to the gashes. They thus 
readily distinguish between the bitter and sweet. The bitter 
are deleterious, but the sweet are quite wholesome. This pe¬ 
culiarity of one species of plants bearing both sweet and bitter 
fruits occurs also in a red eatable cucumber often met with in 
the country. It is about four inches long, and about an inch 
and a half in diameter. It is of a bright scarlet colour when 
j ripe. Many are bitter, others quite sweet. Even Melons in a 
garden may be made bitter by a few bitter Kengwe in the 
vicinity. The bees convey the pollen from one to the other. 
When first taken possession of, these parts are said to have 
been covered with a coating of grass, but that has disappeared 
with the antelopes which fed upon it, and a crop of Mesem- 
bryantliemums and Crassulas occupies its place. It is curious 
to observe how, in nature, organizations the most dissimilar 
are mutually dependent on each other for their perpetuation. 
Here the original grasses were dependent for dissemination 
on the grass-feeding animals, which scattered the seeds. 
When, by the death of the antelopes, no fresh sowing was 
made, the African droughts proved too much for this form 
of vegetation. But even this contingency was foreseen by j 
the Omniscient One ; for, as we may now observe in the 
Kalahari Desert, another family of plants, the Mesem- 
bryanthemums, stood ready to neutralize the aridity which j 
must otherwise have followed. This family of plants pos- I 
sesses seed-vessels which remain firmly shut on their contents j 
while the soil is hot and dry, and thus preserve the vegetative ; 
power intact during the highest heat of the torrid sun ; but 
when rain falls, the seed-vessel opens and sheds its contents 
just when there is the greatest probability of their vegetating. 
In other plants heat and drought cause the seed-vessels to 
burst, and shed their charge. 
One of this family is edible (Mesembryantliemwn edtde) ; 
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 j 
of the greatest drought it shows abundant circulating sap. 
The plants of this family are found much further 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 coloured as to 
blend in well with the hue of the soil and stones around it; 
and a gryllus of the same colour feeds on it. In the case of 
the insect, the peculiar colour 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 gramnivorous ante¬ 
lopes have so abundantly disseminated the seed of grasses. 
A few waggon-loads of Mesembrvanthemum plants, in seed, 
are brought to a farm covered with a scanty crop of coarse 
