Chapter 10

A difficulty might perhaps be raised about birds. How, it may be said, can they, either when they fly or when they walk, be said to move at four points? Now we did not say that all Sanguinea move at four points, but merely at not more than four. Moreover, they cannot as a fact fly if their legs be removed, nor walk without their wings. Even a man does not walk without moving his shoulders. Everything indeed, as we have said, makes a change of place by flexion and straightening, for all things progress by pressing upon what being beneath them up to a point gives way as it were gradually; accordingly, even if there be no flexion in another member, there must be at least in the point whence motion begins, is in feathered (flying) insects at the base of the ‘scale-wing’, in birds at the base of the wing, in others at the base of the corresponding member, the fins¹, for instance, in fish. In others, for example snakes, the flexion begins in the joints² of the body.

In winged creatures the tail serves, like a ship’s rudder, to keep the flying thing in its course. The tail then must like other limbs be able to bend at the point of attachment³. And so flying insects, and birds (Schizoptera) whose tails are ill-adapted for the use in question, for example peacocks, and domestic cocks, and generally birds that hardly fly, cannot steer⁴ a straight course. Flying insects have absolutely no tail, and so drift along like a rudderless vessel⁵, and beat against anything they happen upon; and this applies equally to sharded insects, like the scarab-beetle and the chafer, and to unsharded, like bees and wasps⁶. Further, birds that are not made for flight have a tail that is of no use; for instance the purple coot and the heron and all water-fowl. These fly stretching out their feet as a substitute for a tail, and use their legs instead of a tail to direct their flight. The flight of insects is slow and frail⁷ because the character of their feathery wings is not proportionate to the bulk of their body; this is heavy, their wings small and frail, and so the flight they use is like a cargo⁸ boat attempting to make its voyage with oars⁹; now the frailty¹⁰ both of the actual wings and of the outgrowths upon them contributes in a measure to the flight described. Among birds, the peacock’s tail is at one time useless because of its size, at another because it is shed. But birds are in general at the opposite pole to flying insects as regards their feathers, but especially the swiftest flyers among them. (These are the birds with curved talons¹¹, for swiftness of wing is useful to their mode of life.) The rest of their bodily structure is in harmony with their peculiar¹² movement, the small head, the slight neck, the strong and acute breastbone (acute like the prow¹³ of a clipper-built vessel, so as to be well-girt, and strong by dint¹⁴ of its mass of flesh), in order to be able to push away the air that beats against it, and that easily and without exhaustion¹⁵. The hind-quarters, too, are light and taper¹⁶ again, in order to conform to the movement of the front and not by their breadth to suck the air.

1 fins   

[医]散热片；鱼鳍；飞边；鸭掌

参考例句：

• The level of TNF-α positively correlated with BMI,FPG,HbA1C,TG,FINS and IRI,but not with SBP and DBP. TNF-α水平与BMI、FPG、HbA1C、TG、FINS和IRI呈显著正相关，与SBP、DBP无相关。 来自互联网
• Fins are a feature specific to fish. 鱼鳍是鱼类特有的特征。 来自辞典例句

2 joints   

接头( joint的名词复数 )； 关节； 公共场所（尤指价格低廉的饮食和娱乐场所） （非正式）； 一块烤肉 （英式英语）

参考例句：

• Expansion joints of various kinds are fitted on gas mains. 各种各样的伸缩接头被安装在煤气的总管道上了。
• Expansion joints of various kinds are fitted on steam pipes. 各种各样的伸缩接头被安装在蒸气管道上了。

3 attachment   

n.附属物，附件；依恋；依附

参考例句：

• She has a great attachment to her sister.她十分依恋她的姐姐。
• She's on attachment to the Ministry of Defense.她现在隶属于国防部。

4 steer   

vt.驾驶，为…操舵；引导；vi.驾驶

参考例句：

• If you push the car, I'll steer it.如果你来推车，我就来驾车。
• It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。

5 vessel   

n.船舶；容器，器皿；管，导管，血管

参考例句：

• The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
• You should put the water into a vessel.你应该把水装入容器中。

6 wasps   

黄蜂( wasp的名词复数 )； 胡蜂； 易动怒的人； 刻毒的人

参考例句：

• There's a wasps' nest in that old tree. 那棵老树上有一个黄蜂巢。
• We live in dread not only of unpleasant insects like spiders or wasps, but of quite harmless ones like moths. 我们不仅生活在对象蜘蛛或黄蜂这样的小虫的惧怕中，而且生活在对诸如飞蛾这样无害昆虫的惧怕中

7 frail   

adj.身体虚弱的；易损坏的

参考例句：

• Mrs. Warner is already 96 and too frail to live by herself.华纳太太已经九十六岁了，身体虚弱，不便独居。
• She lay in bed looking particularly frail.她躺在床上，看上去特别虚弱。

8 cargo   

n.(一只船或一架飞机运载的)货物

参考例句：

• The ship has a cargo of about 200 ton.这条船大约有200吨的货物。
• A lot of people discharged the cargo from a ship.许多人从船上卸下货物。

9 oars   

n.桨，橹( oar的名词复数 )；划手v.划（行）( oar的第三人称单数 )

参考例句：

• He pulled as hard as he could on the oars. 他拼命地划桨。
• The sailors are bending to the oars. 水手们在拼命地划桨。 来自《简明英汉词典》

10 frailty   

n.脆弱；意志薄弱

参考例句：

• Despite increasing physical frailty,he continued to write stories.尽管身体越来越虛弱，他仍然继续写小说。
• He paused and suddenly all the frailty and fatigue showed.他顿住了，虚弱与疲惫一下子显露出来。

11 talons   

n.（尤指猛禽的）爪( talon的名词复数 )；（如爪般的）手指；爪状物；锁簧尖状突出部

参考例句：

• The fingers were curved like talons, but they closed on empty air. 他的指头弯得像鹰爪一样，可是抓了个空。 来自英汉文学 - 热爱生命
• The tiger has a pair of talons. 老虎有一对利爪。 来自辞典例句

12 peculiar   

adj.古怪的，异常的；特殊的，特有的

参考例句：

• He walks in a peculiar fashion.他走路的样子很奇特。
• He looked at me with a very peculiar expression.他用一种很奇怪的表情看着我。

13 prow   

n.(飞机)机头，船头

参考例句：

• The prow of the motor-boat cut through the water like a knife.汽艇的船头像一把刀子劈开水面向前行驶。
• He stands on the prow looking at the seadj.他站在船首看着大海。

14 dint   

n.由于，靠；凹坑

参考例句：

• He succeeded by dint of hard work.他靠苦干获得成功。
• He reached the top by dint of great effort.他费了很大的劲终于爬到了顶。

15 exhaustion   

n.耗尽枯竭，疲惫，筋疲力尽，竭尽，详尽无遗的论述

参考例句：

• She slept the sleep of exhaustion.她因疲劳而酣睡。
• His exhaustion was obvious when he fell asleep standing.他站着睡着了，显然是太累了。

16 taper   

n.小蜡烛，尖细，渐弱；adj.尖细的；v.逐渐变小

参考例句：

• You'd better taper off the amount of time given to rest.你最好逐渐地减少休息时间。
• Pulmonary arteries taper towards periphery.肺动脉向周围逐渐变细。