AN ENCYCLOPADIA 
OF HORTICULTURE. 199 
Wasps—continued. 
for about. twenty-four hours, without active movement. 
During this time, the wax is formed in thin plates, one 
in each of the little pockets mentioned above as occurring 
on the three middle segments of the abdomen. When 
the wax is formed, the bee detaches the plates from 
the pockets, and chews them up, mixed with a liquid 
from the mouth, into a riband, which is deposited on 
the place where it is to be made into cells. After the 
wax-makers have deposited the materials, the other class 
of workers build it up into the cell walls, making the 
cells larger or smaller, as required for the females, 
males, and workers. The edges of the cells are 
finished with a kind of adhesive varnish, which melts less 
easily than wax, and is redder in colour. This is the 
* propolis,” which the bees collect from the bud-scales of 
Horse Chestnuts, Poplars, and other trees possessed of 
sticky buds. Attention has frequently been called by 
zoologists and mathematicians to the regularity of form 
and of size in the cells, and also to the fact that their 
form secures the greatest possible inclosed space with 
the smallest possible expenditure of wax. 
Many of the cells are occupied by larve or pupe; 
but others are employed as storehouses for the honey, 
and often the cells from which young bees have emerged 
are cleared out and filled with honey. The visits 
made by bees to flowers, in the course of which they are 
of so great use in effecting pollination in many plants, 
have as their object the collection of nectar and of pollen. 
(see Nectar, Nectary, Orchid Fertilisation, and 
Pollination). The bees swallow the nectar, and continue 
their visits to flowers till the stomach, or honey-bag, is 
filled with the sweet fluid. They then collect the pollen, 
forming little masses of the grains brushed off their 
bodies; they place them upon the hairy, flattened por- 
tions of the hind legs, and they thus form a load of 
food to be carried back to the hive. In the stomach 
the nectar undergoes a change by which it is converted 
into honey, and this is either given at once by the collec- 
tors to those bees that have been at work in the hive, 
as food, or is poured into the cells. Those which contain 
honey that is soon to be used are not closed; but such 
as are reserved for food during winter are covered with 
wax. The pollen is either eaten by the bees themselves, 
or is given to those that have been at work in the nest, 
or to the larvæ, or it is stored away in cells for future use. 
- On these stores the bees subsist during winter; hence 
the nests are not broken up on the approach of cold 
weather: nor do the bees resemble Wasps in destroying 
their larve in autumn, as they can provide them with’ 
food. When the honey is taken from hive bees, it is 
necessary to supply them with sugar and water, or with 
other sugary substances, from which they can prepare 
honey. 
It may be mentioned, in conclusion, that there are 
several kinds of bees in domestication, of which A. mellifica 
is the commonest, and has been specially kept in view 
above ; the other species differ only from it in minor details. 
WATER. Water is so indispensable to the very 
existence of plants, that its use and modes of action 
deserve to be more fully understood than they are by many 
gardeners. It is made up of a combination of two gases, 
Oxygen and Hydrogen, in the proportion of sixteen (by 
weight) of the former to two of the latter. By volume, 
the proportion is one of Oxygen to two of Hydrogen, 
the chemical formula being H,O. The properties of 
Water are, for the most part, so well known as to 
render it needless to dwell upon them. When pure, 
it has neither colour, taste, nor smell; nor does it 
leave any solid matter when it is allowed to evaporate 
by heat or by exposure to the atmosphere. That Water 
is converted into ice, and rain into snow, at a low 
temperature (32deg. Fahr.), is a fact familiar to every- 
one in such a climate as ours. While it is freezing, the 
Water—continued. 
Water frees itself from by far the greater part of mineral 
substances that may be dissolved in it; so that ice 
consists of almost pure Water, even when formed from 
the salt Water of the sea. Pure Water has the power 
of dissolving many mineral substances and gases in greater 
or less amount, the greatest quantity of any particular 
substance or gas that it can dissolve varying with its 
temperature. The solutions thus formed are of very great 
importance in horticulture, since it is in this form that 
plants absorb the elements found in their ash, and which 
are mostly essential to their support. These solutions of 
minerals in the soil are almost always extremely dilute. 
In such weak solutions minerals can be absorbed with 
much greater readiness by the root-hairs of plants than 
they could be were the solutions stronger, so that they are 
well suited to supply the requirements of plants. Some 
minerals—e.g., Carbonate of Lime (whether in the form of 
marble or of chalk)—are scarcely, if at all, soluble in 
pure Water; but they become dissolved in water which 
has Carbonic Acid Gas already dissolved in it. Probably, 
no natural Waters are wholly deficient in this gas, and 
they can dissolve small quantities of even marble or Phos- 
phates of Lime. The roots of plants can themselves also 
dissolve these minerals when in close contact with them. 
In all cases, the minerals necessary for the nutrition of the 
plants pass into them from the soil in these weak solutions. 
There is a constant passage of the fluids into the roots, and 
thence into the leaves, in order to replace the Water that 
is at all times escaping from all the green parts into the 
air in the form of invisible vapour. 
The amount and nature of the water-supply for a 
garden is a matter of very great consequence; and it 
is necessary to inquire a little into the various natural 
sources from which it can be obtained, and the relative 
merits of the Water from each. The sources may be 
grouped under (1) rain, (2) ponds and streams, and 
(3) springs. Though it is impossible to draw sharply- 
defined distinctions between the Waters from these sources, 
yet they differ in several respects. 
Rain is, in a sense, the source from which all Waters 
are derived, and from which all streams are fed; but 
the term Rain-water, in the ordinary sense, is restricted 
to that collected from the atmosphere—usually off the 
roofs of houses—and carried into a tank, in which it 
is stored till required. Pure Rain-water may contain a 
small quantity of Nitrates and Ammonia, which it dis- 
solves out of the atmosphere, and carries with it to the 
earth. But, owing to the dust and impurities on the 
roofs or other surfaces from which it is usually collected, 
it always has also an appreciable, though very small, 
amount of various mineral substances dissolved in it; 
and is thus able to supply to plants at least a part of 
the mineral food that they require. It is fitted also to 
dissolve from the soil in which plants grow such sub- 
stances as Carbonate of Lime, as it almost always contains 
a good deal of Carbonic Acid Gas, and also some Oxygen, 
dissolved while falling through the atmosphere. It is 
heated to the same average temperature as the air, so 
that in summer it helps to warm the soil to that. tem- 
perature ; and it thus stimulates the growth and power 
of absorption of the roots, and fits them to supply Water 
to the plants as quickly as it evaporates from the leaves. 
Rain-water is preferred for watering plants on account 
. of its temperature being nearly the same as the air, and 
of the gases dissolved in it. 
The Water in streams and in ponds contains a larger 
proportion of mineral substances than occurs in pure 
Rain-water, the gases are often present, only in smaller 
amount, and the average temperature — except in very 
shallow streams and ponds—is usuallyslower than that of 
the air in summer; and this is especially the case with 
Water conveyed from a distance in underground pipes. ` 
Spring Water resembles that from streams in the amount 
