Nature's Teachings. John George Wood

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      Whether or not this principle be now employed in warfare I cannot say, but it is at all events used extensively in a small way of hunting, the best known of which is the wire Mouse-trap, one of which is shown at Fig. C on the illustration. A glance at the figure will explain the trap, even to those who have never seen it. It is composed entirely of wire, and has several round holes just above its lower edge. Each of these holes is the entrance to a conical tunnel made of wires with sharpened ends.

      The mouse, being attracted by a bait placed within the trap, tries to get at it. The doomed animal soon finds its way to one of the entrances, and with little difficulty pushes itself through the tunnel. Entering, however, is one thing, and returning is another. The wire yielded easily enough in one direction, but for the mouse to force itself against the converging points is an impossible task.

      Readers of the last century literature may perhaps remember, in the pages of “Peter Pindar,” a very clever and sarcastic account of the astonishment created in the mind of George III. by a mouse-trap seen accidentally in the house of a widow living at Salt Hill.

      For my part I think that the King was quite right. If he did not know the philosophy of a mouse-trap he ought to have asked, and to have been rewarded, as in that case, by catching with a trap of his own baiting, six mice on six successive days.

      At Fig. B on the same illustration is shown the simple apparatus by which crabs and lobsters are caught. The reader will see that the principle is exactly the same in both cases, the only difference being in material, the mouse-trap being made of wire, and the crab-pot of wicker.

      At Fig. D is shown the common Eel-pot, or Eel-basket. In order to suit the peculiar shape of an eel, this basket is much longer in proportion to its diameter than either of the preceding traps, but it is formed on the same plan. An eel can easily pass into the basket through the conical tunnel, but it is next to impossible that it should find its way out again.

      So much for Art, and now for Nature.

      On the left hand of the illustration, at Fig. A, is the cocoon of the common Emperor-moth (Saturnia pavonia minor), the cocoon having been stripped of its outer envelope, so as to allow its structure to be better seen.

      The reader will at once perceive that the entrance of the cocoon is guarded by an arrangement exactly like that of the above-mentioned traps, except that the cone is reversed, so as to allow of exit and to debar entrance. Guarded by this conical arrangement of stout bristly appendages, the pupa can remain in quiet during the time of its transformation, for nothing can force its way through such a defence, and yet the moth, when fully developed, can push its way out with perfect ease.

      So admirably is this cocoon formed, that even after the moth has escaped, it is impossible to tell by mere sight whether or not it is within, the elastic wires closing on it after its passage.

      Another modification of the same principle now comes before us. In the above-mentioned examples the arrangement of the reverted spikes is more or less conical, and they lead into a chamber. In the present instances, however, the mere reversion of the points is all that is needed.

      The upper figure on the right hand represents the “Catchpoll” of the Middle Ages, an allusion to which has already been made. The reverted spikes turn on hinges, and are kept apart by springs. This beautifully formed head was attached to a long shaft, and was used for the purpose of dragging horsemen from the saddle. It was thrust at the neck of the rider, generally from behind. If a successful thrust were made, the spring-points gave way, sprang back again, and thus clasped the neck with a hold that was fatal to the rider.

      Below it is the Deer-trap which is used in many parts of India, and to which allusion has already been made. The reader will see at once that if a deer should get its foot through the converging spikes, its doom is sealed, especially as there is a heavy log of wood attached to the trap by a rope.

      On the left hand of the illustration are two examples of the same principle taken from Nature, one belonging to fresh and the other to salt water.

      The upper figure represents the jaws of a Pike, with their terrible array of reverted teeth. The Pike, as every one knows, feeds upon other fish, and eats them in a curious manner. It darts at them furiously, and generally catches them in the middle of the body. After holding them for a time, for the purpose, as I imagine, of disabling them, it loosens its hold, makes another snap, seizes the fish by the head, and swallows it.

      The Pike is so voracious that it will attack and eat fish not very much smaller than itself, for its digestion is so rapid that the head and shoulders of a swallowed fish have been found to be half digested, while the tail was sticking out of the Pike’s mouth. Unless, therefore, the teeth of the Pike were so formed as to resist any retrograde movement on the part of the prey, the fish would starve; for, lank and lean as it is, the Pike is one of the most voracious creatures in existence, never seeming able to get enough to eat, and yet, as is often found in such cases, capable of sustaining a lengthened fast.

      How well adapted is this СКАЧАТЬ