Nature's Teachings. John George Wood

the same expedition.

      The next illustration exhibits a butcher’s hook and a common porter’s hook, by which he lifts sacks on his back; and opposite them are some sponge-spicules, the similarity of which in form is so remarkable that the former might have been copied from the latter.

      Our next sketch shows a remarkable example of similitude in form. There are certain small anchors called Kedges, which are very useful for mooring a boat where no great power of resistance has to be overcome, and a large anchor would be cumbersome. One of these is called, from its shape, the “Mushroom Kedge,” and is very useful, as, however it may be dropped, some part of the edge is sure to take the ground. This Kedge is shown on the right hand of the illustration, and the Mushroom, from which its shape was borrowed, is seen on the left.

      We now come to some more examples of the principle of the Grapnel, some of which are applied to nautical, and others to terrestrial objects.

      The right-hand upper figure represents the “Flesh-hook,” used for taking boiled meat out of the caldron, so familiar to us by the reference to it in Exodus xxvii. 3, and the still better-known allusion to its office in 1 Samuel ii. 13, 14. In the former passage, even the material, brass, which was really what we now call bronze, is mentioned, and it is a curious fact that all the specimens in the British Museum, from one of which the drawing was taken, are made of bronze. I need hardly state that the hollow handle is meant to receive a wooden staff.

      On comparing this figure with that of the Eagle’s foot on the opposite side, the reader cannot but be struck with the exact resemblance between the two. Indeed, there is very little doubt that the flesh-hook was intentionally copied from the foot of some bird of prey. Perhaps the Osprey would have furnished even a better example than the Eagle, the claws being sharper and more boldly curved, so as to hold their slippery prey the better.

      On the left hand of the next illustration is a figure of the seed-vessel of the Grapple-plant of Southern Africa, drawn from a specimen in my collection. The seed-vessel is several inches in length, and the traveller who is caught by a single hook had better wait for assistance than try to release himself. The stems of the plant are so slender, and the armed seed-vessels so numerous, that in attempting to rescue one portion of the dress, another portion becomes entangled, and the traveller gets hopelessly captured. Besides the hooks of the seed-vessels, the branches themselves are armed with long thorns, set in pairs. The scientific name of this plant is Uncinaria procumbens, the former word signifying “a hook,” and the latter “trailing.” It is also known by the popular name of Hook-plant.

      In the late Kafir wars the natives made great use of this and other plants with similar properties, their own naked, dark, and oiled bodies slipping through them easily and unseen, while the scarlet coats of the soldiers were quickly entangled, and made them an easy mark for the Kafir’s spear. In this way many more of our soldiers were killed by the spears than by the bullets of their enemies.

      Opposite to the Grapple-plant is shown the common Drag, which is utilised for so many purposes. Generally it is employed for recovering objects that have sunk to the bottom of the water, and its use by the officers of the Humane Society is perfectly well known, the Drag being sometimes affixed to the end of a long pole, like the flesh-hook already described, and sometimes tied to a rope.

      It can also be used as an anchor, after the manner of a kedge, and has been often employed in naval engagements for the purpose of drawing two ships together, and preventing the escape of the vessel which is being worsted. My relative, the late Admiral Sir J. Harvey, K.B., used drags in this manner, and secured two French ships, one on either side, namely, L’Achille and Le Vengeur. The first was sunk, and the second captured.

      CHAPTER V.

      SUBSIDIARY APPLIANCES.

      Part III.—The Boat-hook and Punt-pole.—The Life-buoy and Pontoon-raft

      The Boat-hook and its varied Uses.—The Earth-worm and the Serpula.—Microscopic Boat-hooks.—The Life-belt.—Life-boats and their Structure.—Uses of Cork.—Wine Corks made serviceable.—The Life-collar.—Portuguese Man-of-war.—Captain Boyton’s Life-dress.—The Life-raft.—Victualling a Yacht and Boat.—The Janthina and its Air-vessels.—Cask-pontoon—Pottery-raft and its Uses.

      AS all rowing men know, an indispensable appliance to the boat is the Boat-hook, which can be used either as a pole, wherewith to push the boat along, or as a grapnel, by which it can be drawn towards the shore or a ship. As the latter portion has been discussed at the close of the preceding chapter, we may proceed to the former.

      Every one knows how a boat may be propelled by a pole pressed against the bank or the bottom of the water, and that there are certain boats, called punts, which are propelled in no other way.

      Now, the punt-poles and boat-hooks, of which some examples are given in the accompanying illustration, have long been anticipated in Nature, there being many creatures which have no other mode of progression; such, for example, as the common Earth-worm, which pushes itself along by certain bristles which project from the rings of which the body is composed, and which have the power of extension and contraction to a wonderful extent. As, however, I shall advert to these in another part of the work, I will content myself at present with a single example, namely, the beautiful marine worm known as the Serpula.

      This worm lives in a shelly tube, which is lined with a delicate membrane, up and down which it passes with ease, ascending slowly, but generally descending with such wonderful rapidity that the eye cannot follow its movements. The latter movement will be explained in a subsequent part of the book, and we will at present only treat of the former.

      If the creature be removed from the tube, and carefully examined, a number of projections will be seen, in each of which is a perforation. If the animal be pressed, a slight glass-like bristle passes through the perforation, and can easily be removed. If properly treated, and placed under a high power of the microscope, the tiny bristle resolves itself into the remarkable object which is shown on the left hand of the illustration.

      It consists of a number of spear-like rods, each having a straight shaft, and a curved and pointed tip, deeply barbed on the inner portion of the curve. These curious bundles of spicules can be protruded or retracted at pleasure, and, as they are all directed backwards, it is evident that when they are pushed against the sides of the tube, either the points or the barbs must catch against the membrane which lines the tube, and so propel the animal upwards. When it wishes to descend, it uses another set of implements, and withdraws the first within their sheaths.

      This is exactly analogous to the mode of progression employed by punters, who, after they have placed the pole against the bed of the stream, and run along the punt so as to push it as fast as possible, immediately withdraw the pole, and take it to the head of the punt, ready for another push. This, as the reader will see, is exactly the plan pursued by the Serpula in lengthening itself when it wishes to advance, and so to press its spicules against the sides of its tube, and in shortening itself and withdrawing the spicules ready for another push.

      Another needful accessory of vessels now comes before us, namely, the capability of forming rafts or life-belts, which will float under any circumstances. Here, again, every human invention of which I know has been anticipated by Nature. Take, for example, the familiar instance of the cork life-belt and the cork edgings of the life-boat. Both are constructed on the same principle, i.e. the maintenance of cells which are filled by air instead of water, and are impervious to the latter.

      The