Should the feet fall short of this, their deficiency is compensated3 by the power of flight. Of such flying insects some live a wandering life, and are forced to make long expeditions in search of food. These have a body of light weight, and four feathers, two on either side, to support it. Such are bees and the insects akin4 to them. When, however, such insects are of very small bulk, their feathers are reduced to two, as is the case with flies. Insects with heavy bodies and of stationary5 habits, though not polypterous in the same way as bees, yet have sheaths to their feathers to maintain their efficiency. Such are the Melolonthae and the like. For their stationary habits expose their feathers to much greater risks than are run by those of insects that are more constantly in flight, and on this account they are provided with this protecting shield. The feather of an insect has neither barbs6 nor shaft7. For, though it is called a feather, it is no feather at all, but merely a skin-like membrane8 that, owing to its dryness, necessarily becomes detached from the surface of the body, as the fleshy substance grows cold.
These animals then have their bodies insected, not only for the reasons already assigned, but also to enable them to curl round in such a manner as may protect them from injury; for such insects as have long bodies can roll themselves up, which would be impossible were it not for the insections; and those that cannot do this can yet draw their segments up into the insected spaces, and so increase the hardness of their bodies. This can be felt quite plainly by putting the finger on one of the insects, for instance, known as Canthari. The touch frightens the insect, and it remains9 motionless, while its body becomes hard. The division of the body into segments is also a necessary result of there being several supreme10 organs in place of one; and this again is a part of the essential constitution of insects, and is a character which approximates them to plants. For as plants, though cut into pieces, can still live, so also can insects. There is, however, this difference between the two cases, that the portions of the divided insect live only for a limited time, whereas the portions of the plant live on and attain11 the perfect form of the whole, so that from one single plant you may obtain two or more.
Some insects are also provided with another means of protection against their enemies, namely a sting. In some this is in front, connected with the tongue, in others behind at the posterior end. For just as the organ of smell in elephants answers several uses, serving alike as a weapon and for purposes of nutrition, so does also the sting, when placed in connexion with the tongue, as in some insects, answer more than one end. For it is the instrument through which they derive13 their sensations of food, as well as that with which they suck it up and bring it to the mouth. Such of these insects as have no anterior14 sting are provided with teeth, which serve in some of them for biting the food, and in others for its prehension and conveyance15 to the mouth. Such are their uses, for instance, in ants and all the various kinds of bees. As for the insects that have a sting behind, this weapon is given them because they are of a fierce disposition16. In some of them the sting is lodged17 inside the body, in bees, for example, and wasps19. For these insects are made for flight, and were their sting external and of delicate make it would soon get spoiled; and if, on the other hand, it were of thicker build, as in scorpions20, its weight would be an incumbrance. As for scorpions that live on the ground and have a tail, their sting must be set upon this, as otherwise it would be of no use as a weapon. Dipterous insects never have a posterior sting. For the very reason of their being dipterous is that they are small and weak, and therefore require no more than two feathers to support their light weight; and the same reason which reduces their feathers to two causes their sting to be in front; for their strength is not sufficient to allow them to strike efficiently21 with the hinder part of the body. Polypterous insects, on the other hand, are of greater bulk-indeed it is this which causes them to have so many feathers; and their greater size makes them stronger in their hinder parts. The sting of such insects is therefore placed behind. Now it is better, when possible, that one and the same instrument shall not be made to serve several dissimilar uses; but that there shall be one organ to serve as a weapon, which can then be very sharp, and a distinct one to serve as a tongue, which can then be of spongy texture22 and fit to absorb nutriment. Whenever, therefore, nature is able to provide two separate instruments for two separate uses, without the one hampering23 the other, she does so, instead of acting24 like a coppersmith who for cheapness makes a spit and lampholder in one. It is only when this is impossible that she uses one organ for several functions.
The anterior legs are in some cases longer than the others, that they may serve to wipe away any foreign matter that may lodge18 on the insect’s eyes and obstruct25 its sight, which already is not very distinct owing to the eyes being made of a hard substance. Flies and bees and the like may be constantly seen thus dressing26 themselves with crossed forelegs. Of the other legs, the hinder are bigger than the middle pair, both to aid in running and also that the insect, when it takes flight, may spring more easily from the ground. This difference is still more marked in such insects as leap, in locusts27 for instance, and in the various kinds of fleas28. For these first bend and then extend the legs, and, by doing so, are necessarily shot up from the ground. It is only the hind12 legs of locusts, and not the front ones, that resemble the steering29 oars30 of a ship. For this requires that the joint31 shall be deflected32 inwards, and such is never the case with the anterior limbs. The whole number of legs, including those used in leaping, is six in all these insects.
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1
compensate
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| vt.补偿，赔偿；酬报 vi.弥补；补偿；抵消 | |
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2
frigidity
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| n.寒冷；冷淡；索然无味；（尤指妇女的）性感缺失 | |
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3
compensated
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| 补偿，报酬( compensate的过去式和过去分词 )； 给（某人）赔偿（或赔款） | |
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4
akin
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| adj.同族的，类似的 | |
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5
stationary
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| adj.固定的，静止不动的 | |
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6
barbs
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| n.（箭头、鱼钩等的）倒钩( barb的名词复数 )；带刺的话；毕露的锋芒；钩状毛 | |
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7
shaft
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| n.(工具的)柄，杆状物 | |
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8
membrane
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| n.薄膜，膜皮，羊皮纸 | |
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9
remains
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| n.剩余物，残留物；遗体，遗迹 | |
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10
supreme
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| adj.极度的，最重要的；至高的，最高的 | |
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11
attain
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| vt.达到，获得，完成 | |
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12
hind
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| adj.后面的，后部的 | |
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13
derive
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| v.取得；导出；引申；来自；源自；出自 | |
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14
anterior
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| adj.较早的；在前的 | |
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15
conveyance
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| n.(不动产等的)转让，让与；转让证书；传送；运送；表达；（正）运输工具 | |
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16
disposition
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| n.性情，性格；意向，倾向；排列，部署 | |
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17
lodged
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| v.存放( lodge的过去式和过去分词 )；暂住；埋入；（权利、权威等）归属 | |
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18
lodge
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| v.临时住宿，寄宿，寄存，容纳；n.传达室，小旅馆 | |
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19
wasps
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| 黄蜂( wasp的名词复数 )； 胡蜂； 易动怒的人； 刻毒的人 | |
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20
scorpions
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| n.蝎子( scorpion的名词复数 ) | |
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21
efficiently
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| adv.高效率地，有能力地 | |
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22
texture
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| n.(织物)质地；(材料)构造；结构；肌理 | |
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23
hampering
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| 妨碍，束缚，限制( hamper的现在分词 ) | |
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24
acting
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| n.演戏，行为，假装；adj.代理的，临时的，演出用的 | |
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25
obstruct
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| v.阻隔，阻塞(道路、通道等)；n.阻碍物，障碍物 | |
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26
dressing
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| n.(食物)调料；包扎伤口的用品，敷料 | |
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27
locusts
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| n.蝗虫( locust的名词复数 )；贪吃的人；破坏者；槐树 | |
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28
fleas
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| n.跳蚤( flea的名词复数 )；爱财如命；没好气地（拒绝某人的要求） | |
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29
steering
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| n.操舵装置 | |
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30
oars
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| n.桨，橹( oar的名词复数 )；划手v.划（行）( oar的第三人称单数 ) | |
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31
joint
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| adj.联合的，共同的；n.关节，接合处；v.连接，贴合 | |
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32
deflected
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| 偏离的 | |
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