Page:Hardwicke's Science-Gossip - Volume 1.pdf/192

a proper seaweed-press, containing about a dozen smoothly-planed boards; it takes up very little space, and in travelling, the papers, calicoes, and blotters may be placed between the boards. The figure below represents the press which I have employed for years; and on it lies the iron clamp by means of which any requisite amount of pressure may be obtained by tightening the screws, which cap the iron rods connecting

the cross-beams of wood enclosing the pressure-boards. Residents in and around London may examine this press on application at the office of this journal.

Space will not admit of any further description of the process of seaweed-mounting; but I hope that the few directions I have given will help beginners to dry any pretty plants they may meet with.

Enough for all!—A thousand million of men at least now live upon the earth, each one different from his fellows; for every man how many thousand animals, again most different; for every animal how many plants,—still no two quite alike. And yet for all this countless host, for every individual man and animal and plant, there is ample provision in the treasures of the earth and sea and sky; there is abundant flood of sunshine to illumine, warm, and energize the whole; a provision as varied as the wants of those supplied, adjusted carefully to each several need; a flood of sunshine everywhere alike, yet bearing in itself such diverse powers, such adaptive suppleness as perfectly to harmonize with all; sunshine which is gone almost as soon as come, which is scattered far and wide, to all appearance lost, yet in its momentary stay conferring what stupendous blessings!—Warington's Phenomena of Radiation.

During summer the under surface of the leaves of the Common Bramble will commonly be found spotted with a yellow rust. As autumn approaches, darker bodies will be found mixed with this yellow powder, until at last the yellow spores will scarcely be found, but large blackish spots will occupy their place, and reddish spots on the upper surface of the leaf will indicate the presence of the parasite beneath. These dark spots are clusters of spores of the Bramble brand, as figured above. The head consists of an elongated, brown, sausage-shaped fruit, apparently divided by three partitions into four equal-sized cells. (The number is not entirely constant.) These fruits are borne on long colourless stalks or peduncles, which are thickened and almost bulbous at the base.

If some of these spores are removed on the point of a sharp penknife and placed on a slide in a drop of alcohol, and before the spirit is quite evaporated, two or three drops of strong nitric acid are added, and the whole covered with thin glass; if the slide is then warmed over a spirit-lamp to nearly boiling-point, the fruit will be found to consist of an outer membrane, studded with tubercles, enclosing three or four cells. When the membrane is dissolved or ruptured, these cells escape. The apparent divisions of the fruit will be found to be due to the compression of the cells within the membrane. (See "Microscopic Fungi," p. 70.)

The spores may be mounted in glycerine or balsam, and form very interesting objects.^[1]