go. If they attempt to escape by climbing the side, it yields beneath their feet, and the ant-lion beneath pelts them with sand in such a manner, as soon to put an end to their endeavors; having fed upon his prey, the ant-lion, in order to save his reputation, throws the skin to a considerable distance. After having led this life for two years, the ant-lion is promoted to the rank of a fly. The English naturalists have noticed a kind of spider, which, having observed that many insects fall into the water, thinks that his best harvest is there; but nature has neither formed him for swimming, nor provided him with shipping. He does what man would do in a similar case. He collects materials on the shore to form a raft, ties them together with silken strings, and pushing off from the shore, sails out to relieve any insect that may happen to be drowning, not, as may well be supposed, from motives of pure humanity, but rather of that mixed kind which enters so largely into most actions in this world. What ideas insects have upon the subject of social rights and claims, we do not know. They are active enough in relieving each other while living; but let an unfortunate insect be taken sick, and they gather about him and put him out of his pain. Whether they think that if he must die, the sooner the better, or whether this is the means which nature has provided for shortening the agony of death, it is upon the whole a benefit to those which are subjects of the operation. The female bees make a general massacre of the drones; wasps, on the approach of winter, as they do not make any provision against the evils of cold and hunger, murder their young, on Sancho's principle, that there is no pain so great which death cannot end. Some suppose that insects and other animals do not suffer as we do from such an operation; the main reason upon which they support the theory is the cheerfulness with which the insects submit to it; but this may arise from other causes; besides, they are not in the habit of expressing their feelings. It will be better for the sake of humanity, to go on the presumption that they suffer, because the doubts upon the subject are not easily removed. The motions of insects are very curious, and some of them have occasioned much controversy and speculation. Apodous larvæ have no occasion to take long journeys, their business confines them at home; they therefore make their way slowly, by gliding, jumping or swimming, ways sufficiently rapid for their purpose. The motion of serpents, in old time was accounted very mysterious; no one could tell how they moved so rapidly, without any visible means of walking, and this was among the reasons which gained for them so much reverence in ancient times. Sir Everard Home at last discovered, that the points of their ribs were curiously constructed for the purpose; and in the same way it is probable that many things of the kind, which are now incomprehensible, will appear to be very simple. Some move by contracting the segments of their bodies; others, like the larvæ of flies, drag themselves by hooks in the head, an operation as inconvenient as if a man should drag himself on the ground by his chin; cheese-maggots fix their mandibles in places on the table, and let them go with a jerk which sends them to a marvellous distance. Caterpillars climb very readily, but for security carry a ladder of ropes as they go, sticking it to glass or any substance, however hard and smooth, on which they happen to be ascending. They often have occasion to descend from branch to branch; sometimes they are shaken by the wind or thrown with violence to the ground, in which case they take their rope with them, and by means of it re-ascend the tree. So when they travel round the tree, they need a clue to conduct them back to the nest. When they move, they reach forward their necks as far as possible, fasten the thread, then bring up their body and take another step, a movement which may be seen in the cankerworm of our orchards. When they descend, they have power to contract the orifice through which they send out their thread, so as to let themselves gradually down. In climbing on the line, the caterpillar catches the thread as high as it can reach, pulls up its body, grasps the thread with its hindmost legs, and thus regains the tree from which it had fallen. When it has thus ascended, it is found to have a little ball of thread. The motion of flies was long a subject of debate and wonder; some thought that they must have claws, others that they had glutinous sponges, an appendage which would not allow of rapid motion. Hooke was the first to observe, that some curious mechanism must be employed, but what it was he could not discover; he thought it might be something resembling cardteeth, set opposite to each other, by which they could grapple some projecting places, such as they might find on the smoothest surfaces. Durham thought it not unlikely that they stuck, as boys lift a lap-stone by a piece of wet leather attached to VOL. XXXV.NO. 76. 29 the top; an explanation which amounted to nothing more than a confession of ignorance; since, though it might show how a fly could stick to a wall, the object was to show how they move on the wall. Sir Everard Home at last discovered, that it was done by producing a vacuum between the surface on which they walk and parts of the foot constructed for that purpose. There are two suckers connected with the last joint of the tarsus, and a narrow neck which moves in all directions, under the root of each claw. These suckers consist of a contractile membrane, which adapts itself to any surface. Had it been possible for the fly to communicate with men, the air-pump of Guericke, and possibly our countryman Dr. Prince's improvement upon it, might have been known to the world much sooner after it was created. There is a water-spider, also, which invented the diving-bell and has used it to more purpose than men. It spins a shell of closely woven white silk, in the form of half a pigeon's egg, which forms the diving-bell. This is sometimes under, sometimes partly above the surface of the water, and is lashed by threads to whatever happens to be near. It is closed all round except an opening below. By this contrivance, the spider carries air with it down to its submarine nest. To complete the catalogue of mathematical instruments, it is well known, that the gossamer spider ascends high into the air with its light thread, on the principle of the balloon. The movement of spiders in the air has always been regarded as a difficult matter to explain. Dr. Lister, the celebrated English naturalist, whose researches into the habits of spiders discovered almost all that is now known, believed that they had the power of shooting out threads in the direction in which they wished to go. Kirby also used the same language, speaking of the spider shooting out his threads,' not from carelessness of expression, but evidently meaning to be literally understood. White of Selborne gives the same account of the spider. This certainly is a great weight of authority in favor of this power in the spider; but it is so unlike every thing with which we are acquainted, that we are naturally suspicious of some mistake, and we are glad to see that Mr. Rennie will not allow, that the spider has a gift so much beyond the usual order of nature. There are those of no small pretensions as naturalists, who believe that the floating of the spider's thread is electrical, and maintain that it can dart its thread in the wind's eye. Whoever hastily observes them will be of the same opinion, with respect to the gossamer spider and some others. Within a few days, standing in a shed, we saw a line of very small spiders coming down perpendicularly from the wall, each being apparently attached to a large thread by a smaller thread of its own. There were perhaps a hundred in the string. After having descended about eight or ten feet, the lowest came opposite to a door, where a light air was blowing in, and turned off in a direction almost horizontal towards the door. On looking very closely, we could discover no line beyond the leading spider, but on striking the hand between him and the wall, he immediately fell into the perpendicular again. It is difficult to believe that spiders have sufficient projectile force to dart out a thread of such a material to any considerable distance, and the general opinion now is, that they depend wholly upon the lightness of their thread and the agitation of the air, In the Insect Miscellanies, Mr. Rennie discusses some curious subjects connected with insects, which were not embraced in the design of his former works. One is, the manner in which insects are guided in their flight, not so much by their sight, as by the delicate nerves of their wings; in this power resembling bats, which, as is proved by some humane experiments, can find their way as well without eyes as with them. Another is the sensibility of insects to changes of temperature. Mr. Rennie does not seem to think very highly of their observations of the weather. We had supposed that they equalled the most nervous invalid in their sensibility; ants are known to secure their eggs against the rain, and there seems to be no reason, why spiders should not be equally accurate observers. There are flowers which foretell such changes, and if such presages are necessary to the existence of the insect, doubtless their instinct supplies them. They probably are not much acquainted with causes and effects; but instinct is the direct agency of a power which is not limited in its capacities. It is no acquaintance with the principles which govern the ordnance department, which induces the insect called the bombardier to discharge its artillery upon any insect which pursues it; it is frequently chased by other insects, and instead of retreating, it waits till they come within point-blank shot, and then discharges its fieldpiece with a noise and smoke which to insects are truly alarming. In this way it will fire as many as twenty rounds, and when its ammunition is exhausted, if the pursuer is not repelled, the gunner will retreat to a shelter, retiring, not with alarm, but with a very imposing front, like the Americans at Bunker Hill. Mr. Rennie adds to the curious particulars already known, concerning the manner in which grasshoppers produce and increase their sound. They apply the hind shank to the thigh, rubbing it smartly against the wing-case, and alternately the right and left legs. This fiddling, however, would not be heard at any great distance, were it not for a sort of drum at their side, which is formed with membranes suited to increase and echo the sound. The instrument upon which the male cricket plays,-for, unlike the usual order of nature, the female is silent,-is a pair of rough strings in the wing-cases, which they rub against each other. White of Selborne endeavored to naturalize field crickets near his house, and Mr. Rennie to introduce house crickets to his hearth; both were unsuccessful, the insects probably having doubts whether their first welcome would ripen into lasting hospitality. These are certainly very interesting works, and do credit to the Library of Entertaining Knowledge, of which they form a part, as well as to the ability of Mr. Rennie, as a naturalist and a writer. We do not expect sudden nor striking effects from thus multiplying works of popular instruction, but when they are sown broad-cast, as they are in the present day, some will take root, and produce harvests which the world does not know. To supply means of happiness,-to inspire a taste and talent for observation, to teach men to pass through the world, not as strangers, but as interested to know every thing about them, though it may not be so splendid a service as many other scientific exertions, is certainly the one which will give the philosopher his most enviable and enduring fame. A.N. Everett, ART. X.-Bigelow's Travels in Malta and Sicily. It is well observed by Pliny, that history, however written, is always delightful. Historia, quoquo modo scripta, delectat. The same remark may be applied to travels; and it may be added with regard to both these classes of works, that they are always instructive. They are the true antidote to the mass of |