Can the rush grow up without mire? Can the flag grow without water?-JOB.

There, fed by food they love, to rankest size,
Around the dwelling docks and wormwood rise;
Here the strong mallow strikes her slimy root;
Here the dull nightshade hangs her deadly fruit;
On hills of dust the henbane's faded green,
And pencilled flowers of sickly scent is seen,

At the wall's base the fiery nettle springs,
With fruit globose, and fierce with poisoned stings.
Above, the growth of many a year, is spread
The yellow level of the stonecrop's bed;
In every chink delights the fern to grow
With glossy leaf and tawny bloom below.

CRABBE.

To enter into any lengthened detail on the all-important subject of the Natural Conditions of Plants would occupy far too much space; yet to pass it by without special notice, in any work treating of their cultivation, would be impossible. Without a knowledge of the laws which regulate their growth, all our attempts must be empirical

and more or less abortive. When we survey the vegetation on the surface of the earth, we are struck with the endless diversities of form which present themselves to our astonished gaze, from the magnificent palms of the Tropics and the bread-fruit of the Polynesian Islands to the reindeer moss of Lapland, or the red snow of the Arctic regions. Yet the growth of all is governed by immutable laws, and they owe their varying forms to varying climatal conditions.

In Rome upon Palm Sunday
They bear true palms,
The Cardinals bow reverently

And sing old Psalms:
Elsewhere their Psalms are sung

'Mid olive branches.

The holly bough supplies their place

Among the avalanches :

More northern climes must be content

With the sad willow.-GOETHE.

HEAT.

The heat to which plants are subjected varies from 30° or 40° below zero to 170° or 180° Fahr. In Spitzbergen, the earth in the middle of the short summer is never thawed to more than the depth of a few inches, and the stem of the only tree, a little willow, if tree it can be called, runs under ground for several feet within an inch or two of the never-melting ice, whilst in Mexico

the heat rises to 170° or 180°, and the ground is occupied by cactuses, whose structure is such as to enable them to resist the extremest degree of drought. Were it not for such plants, these hot regions would form impassable barriers between neighbouring countries. No water is to be found in these districts, nor anything to eat save the fruit of the Petaya, which Hardy tells us was the sole subsistence of himself and his party for four days. This, unlike other luscious fruit, rather allays than creates thirst, while, at the same time it satisfies, to a certain degree, the sensation of hunger. St. Pierre calls the cactuses, the "Springs of the Desert." The wild ass of the Llanos, too, knows well how to avail himself of these plants. In the dry season, when all animal life flies from the glowing Pampas, when cayman and boa sink into deathlike sleep in the dried-up mud; the wild ass alone, traversing the steppes, knows how to quench his thirst, cautiously stripping off the dangerous spines of the melocactus with his hoof, and then, in safety, sucking the cooling vegetable juice. The Providence of God is equally manifested in cold countries, as in Lapland—where the rein-deer moss furnishes the sole food, during winter, of the rein-deer, without which the inhabitants could not exist.

LIGHT.

"Even as the soil which April's gentle showers

Have filled with sweetness, and enriched with flowers,
her suckling plants, still shooting forth

Rears

up
The tender blossoms of her timely birth;

But if denied the beams of cheerly May,

They hang their withered heads and fade away.”

It is hardly possible to overrate the influence of light upon plants. Its intensity, however, varies exceedingly. Sir J. W. Herschel says that the light at the Cape of Good Hope, when compared with that of our brightest summer's day in England, is as 44° to 27°. In other situations, plants are found growing where the light is not more than half of what would be given by an ordinary candle. Very much of our success in horticulture depends upon the proper amount of light; and, the fact that flowering plants generally require more light than ferns, is one principal reason why the former do not succeed so well in closed cases in rooms, as the latter. A plant of Linaria Cymballaria lived for some years in a closed case on the top of a model of a portion of Tintern Abbey. The branches which grew towards the light, invariably produced leaves of the full size, with perfect flowers and fruit, whilst those branches