5 Theory of Protective Colouring

We will now endeavour to show how these wonderful resemblances have most probably been brought about. Returning to the higher animals, let us consider the remarkable¹ fact of the rarity of white colouring in the mammalia or birds of the temperate² or tropical zones in a state of nature. There is not a single white land-bird or quadruped in Europe, except the few arctic or alpine³ species, to which white is a protective colour. Yet in many of these creatures there seems to be no inherent tendency to avoid white, for directly they are domesticated⁴ white varieties arise, and appear to thrive as well as others. We have white mice and rats, white cats, horses, dogs, and cattle, white poultry⁵, pigeons, turkeys, and ducks, and white rabbits. Some of these animals have been domesticated for a long period, others only for a few centuries; but in almost every case in which an animal has been thoroughly⁶ domesticated, parti-coloured and white varieties are produced and become permanent.

It is also well known that animals in a state of nature produce white varieties occasionally. Blackbirds, starlings, and crows are occasionally seen white, as well as elephants, deer, tigers, hares, moles⁷, and many other animals; but in no case is a permanent white race produced. Now there are no statistics to show that the normal-coloured parents produce white offspring oftener under domestication⁹ than in a state of nature, and we have no right to make such an assumption if the facts can be accounted for without it. But if the colours of animals do really, in the various instances already adduced, serve for their concealment¹⁰ and preservation¹², then white or any other conspicuous¹³ colour must be hurtful, and must in most cases shorten an animal’s life. A white rabbit would be more surely the prey¹⁴ of hawk¹⁵ or buzzard, and the white mole⁸, or field mouse, could not long escape from the vigilant¹⁶ owl¹⁷. So, also, any deviation¹⁸ from those tints²⁰ best adapted to conceal¹¹ a carnivorous animal would render the pursuit of its prey much more difficult, would place it at a disadvantage among its fellows, and in a time of scarcity²¹ would probably cause it to starve to death. On the other hand, if an animal spreads from a temperate into an arctic district, the conditions are changed. During a large portion of the year, and just when the struggle for existence is most severe, white is the prevailing²² tint¹⁹ of nature, and dark colours will be the most conspicuous. The white varieties will now have an advantage; they will escape from their enemies or will secure food, while their brown companions will be devoured²³ or will starve; and as “like produces like” is the established rule in nature, the white race will become permanently²⁴ established, and dark varieties, when they occasionally appear, will soon die out from their want of adaptation to their environment. In each case the fittest will survive, and a race will be eventually produced adapted to the conditions in which it lives.

We have here an illustration of the simple and effectual means by which animals are brought into harmony with the rest of nature. That slight amount of variability in every species, which we often look upon as something accidental or abnormal, or so insignificant²⁵ as to be hardly worthy²⁶ of notice, is yet the foundation of all those wonderful and harmonious²⁷ resemblances which play such an important part in the economy of nature. Variation is generally very small in amount, but it is all that is required, because the change in the external conditions to which an animal is subject is generally very slow and intermittent²⁸. When these changes have taken place too rapidly, the result has often been the extinction²⁹ of species; but the general rule is, that climatal and geological changes go on slowly, and the slight but continual variations in the colour, form, and structure of all animals, has furnished individuals adapted to these changes, and who have become the progenitors³⁰ of modified races. Rapid multiplication³¹, incessant³² slight variation, and survival of the fittest — these are the laws which ever keep the organic world in harmony with the inorganic³³, and with itself. These are the laws which we believe have produced all the cases of protective resemblance already adduced, as well as those still more curious examples we have yet to bring before our readers.

It must always be borne in mind that the more wonderful examples, in which there is not only a general but a special resemblance — as in the walking leaf, the mossy phasma, and the leaf-winged butterfly — represent those few instances in which the process of modification³⁴ has been going on during an immense series of generations. They all occur in the tropics, where the conditions of existence are the most favourable³⁵, and where climatic changes have for long periods been hardly perceptible. In most of them favourable variations both of colour, form, structure, and instinct or habit, must have occurred to produce the perfect adaptation we now behold³⁶. All these are known to vary, and favourable variations when not accompanied by others that were unfavourable, would certainly survive. At one time a little step might be made in this direction, at another time in that — a change of conditions might sometimes render useless that which it had taken ages to produce — great and sudden physical modifications³⁷ might often produce the extinction of a race just as it was approaching perfection, and a hundred checks of which we can know nothing may have retarded³⁸ the progress towards perfect adaptation; so that we can hardly wonder at there being so few cases in which a completely successful result has been attained³⁹ as shown by the abundance and wide diffusion⁴⁰ of the creatures so protected.

1 remarkable   

adj.显著的，异常的，非凡的，值得注意的

参考例句：

• She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
• These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。

2 temperate   

adj.温和的，温带的，自我克制的，不过分的

参考例句：

• Asia extends across the frigid,temperate and tropical zones.亚洲地跨寒、温、热三带。
• Great Britain has a temperate climate.英国气候温和。

3 alpine   

adj.高山的；n.高山植物

参考例句：

• Alpine flowers are abundant there.那里有很多高山地带的花。
• Its main attractions are alpine lakes and waterfalls .它以高山湖泊和瀑布群为主要特色。

4 domesticated   

adj.喜欢家庭生活的；（指动物）被驯养了的v.驯化( domesticate的过去式和过去分词 )

参考例句：

• He is thoroughly domesticated and cooks a delicious chicken casserole. 他精于家务，烹制的砂锅炖小鸡非常可口。 来自《简明英汉词典》
• The donkey is a domesticated form of the African wild ass. 驴是非洲野驴的一种已驯化的品种。 来自《简明英汉词典》

5 poultry   

n.家禽，禽肉

参考例句：

• There is not much poultry in the shops. 商店里禽肉不太多。
• What do you feed the poultry on? 你们用什么饲料喂养家禽?

6 thoroughly   

adv.完全地，彻底地，十足地

参考例句：

• The soil must be thoroughly turned over before planting.一定要先把土地深翻一遍再下种。
• The soldiers have been thoroughly instructed in the care of their weapons.士兵们都系统地接受过保护武器的训练。

7 moles   

防波堤( mole的名词复数 )； 鼹鼠； 痣； 间谍

参考例句：

• Unsightly moles can be removed surgically. 不雅观的痣可以手术去除。
• Two moles of epoxy react with one mole of A-1100. 两个克分子环氧与一个克分子A－1100反应。

8 mole   

n.胎块；痣；克分子

参考例句：

• She had a tiny mole on her cheek.她的面颊上有一颗小黑痣。
• The young girl felt very self- conscious about the large mole on her chin.那位年轻姑娘对自己下巴上的一颗大痣感到很不自在。

9 domestication   

n.驯养，驯化

参考例句：

• The first was the domestication of animals. 第一个阶段是驯养动物。 来自《简明英汉词典》
• In northwestern China, there is no evidence for endemic domestication of any animals. 在中国西北，没有任何当地动物驯化的迹象。 来自辞典例句

10 concealment   

n.隐藏, 掩盖，隐瞒

参考例句：

• the concealment of crime 对罪行的隐瞒
• Stay in concealment until the danger has passed. 把自己藏起来，待危险过去后再出来。

11 conceal   

v.隐藏，隐瞒，隐蔽

参考例句：

• He had to conceal his identity to escape the police.为了躲避警方，他只好隐瞒身份。
• He could hardly conceal his joy at his departure.他几乎掩饰不住临行时的喜悦。

12 preservation   

n.保护，维护，保存，保留，保持

参考例句：

• The police are responsible for the preservation of law and order.警察负责维持法律与秩序。
• The picture is in an excellent state of preservation.这幅画保存得极为完好。

13 conspicuous   

adj.明眼的，惹人注目的；炫耀的，摆阔气的

参考例句：

• It is conspicuous that smoking is harmful to health.很明显，抽烟对健康有害。
• Its colouring makes it highly conspicuous.它的色彩使它非常惹人注目。

14 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

15 hawk   

n.鹰，骗子；鹰派成员

参考例句：

• The hawk swooped down on the rabbit and killed it.鹰猛地朝兔子扑下来,并把它杀死。
• The hawk snatched the chicken and flew away.老鹰叼了小鸡就飞走了。

16 vigilant   

adj.警觉的，警戒的，警惕的

参考例句：

• He has to learn how to remain vigilant through these long nights.他得学会如何在这漫长的黑夜里保持警觉。
• The dog kept a vigilant guard over the house.这只狗警醒地守护着这所房屋。

17 owl   

n.猫头鹰，枭

参考例句：

• Her new glasses make her look like an owl.她的新眼镜让她看上去像只猫头鹰。
• I'm a night owl and seldom go to bed until after midnight.我睡得很晚，经常半夜后才睡觉。

18 deviation   

n.背离，偏离；偏差，偏向；离题

参考例句：

• Deviation from this rule are very rare.很少有违反这条规则的。
• Any deviation from the party's faith is seen as betrayal.任何对党的信仰的偏离被视作背叛。

19 tint   

n.淡色，浅色；染发剂；vt.着以淡淡的颜色

参考例句：

• You can't get up that naturalness and artless rosy tint in after days.你今后不再会有这种自然和朴实无华的红润脸色。
• She gave me instructions on how to apply the tint.她告诉我如何使用染发剂。

20 tints   

色彩( tint的名词复数 )； 带白的颜色； （淡色）染发剂； 痕迹

参考例句：

• leaves with red and gold autumn tints 金秋时节略呈红黄色的树叶
• The whole countryside glowed with autumn tints. 乡间处处呈现出灿烂的秋色。

21 scarcity   

n.缺乏，不足，萧条

参考例句：

• The scarcity of skilled workers is worrying the government.熟练工人的缺乏困扰着政府。
• The scarcity of fruit was caused by the drought.水果供不应求是由于干旱造成的。

22 prevailing   

adj.盛行的；占优势的；主要的

参考例句：

• She wears a fashionable hair style prevailing in the city.她的发型是这个城市流行的款式。
• This reflects attitudes and values prevailing in society.这反映了社会上盛行的态度和价值观。

23 devoured   

吞没( devour的过去式和过去分词 )； 耗尽； 津津有味地看； 狼吞虎咽地吃光

参考例句：

• She devoured everything she could lay her hands on: books, magazines and newspapers. 无论是书、杂志，还是报纸，只要能弄得到，她都看得津津有味。
• The lions devoured a zebra in a short time. 狮子一会儿就吃掉了一匹斑马。

24 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

25 insignificant   

adj.无关紧要的，可忽略的，无意义的

参考例句：

• In winter the effect was found to be insignificant.在冬季，这种作用是不明显的。
• This problem was insignificant compared to others she faced.这一问题与她面临的其他问题比较起来算不得什么。

26 worthy   

adj.(of)值得的，配得上的；有价值的

参考例句：

• I did not esteem him to be worthy of trust.我认为他不值得信赖。
• There occurred nothing that was worthy to be mentioned.没有值得一提的事发生。

27 harmonious   

adj.和睦的，调和的，和谐的，协调的

参考例句：

• Their harmonious relationship resulted in part from their similar goals.他们关系融洽的部分原因是他们有着相似的目标。
• The room was painted in harmonious colors.房间油漆得色彩调和。

28 intermittent   

adj.间歇的，断断续续的

参考例句：

• Did you hear the intermittent sound outside?你听见外面时断时续的声音了吗？
• In the daytime intermittent rains freshened all the earth.白天里，时断时续地下着雨，使整个大地都生气勃勃了。

29 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

30 progenitors   

n.祖先( progenitor的名词复数 )；先驱；前辈；原本

参考例句：

• The researchers also showed that the progenitors mature into neurons in Petri dishes. 研究人员还表示，在佩特里培养皿中的脑细胞前体可以发育成神经元。 来自英汉非文学 - 生命科学 - 大脑与疾病
• Though I am poor and wretched now, my progenitors were famously wealthy. 别看我现在穷困潦倒，我家上世可是有名的富翁。 来自互联网

31 multiplication   

n.增加，增多，倍增；增殖，繁殖；乘法

参考例句：

• Our teacher used to drum our multiplication tables into us.我们老师过去老是让我们反覆背诵乘法表。
• The multiplication of numbers has made our club building too small.会员的增加使得我们的俱乐部拥挤不堪。

32 incessant   

adj.不停的，连续的

参考例句：

• We have had incessant snowfall since yesterday afternoon.从昨天下午开始就持续不断地下雪。
• She is tired of his incessant demands for affection.她厌倦了他对感情的不断索取。

33 inorganic   

adj.无生物的；无机的

参考例句：

• The fundamentals of inorganic chemistry are very important.无机化学的基础很重要。
• This chemical plant recently bought a large quantity of inorganic salt.这家化工厂又买进了大量的无机盐。

34 modification   

n.修改，改进，缓和，减轻

参考例句：

• The law,in its present form,is unjust;it needs modification.现行的法律是不公正的，它需要修改。
• The design requires considerable modification.这个设计需要作大的修改。

35 favourable   

adj.赞成的，称赞的，有利的，良好的，顺利的

参考例句：

• The company will lend you money on very favourable terms.这家公司将以非常优惠的条件借钱给你。
• We found that most people are favourable to the idea.我们发现大多数人同意这个意见。

36 behold   

v.看，注视，看到

参考例句：

• The industry of these little ants is wonderful to behold.这些小蚂蚁辛勤劳动的样子看上去真令人惊叹。
• The sunrise at the seaside was quite a sight to behold.海滨日出真是个奇景。

37 modifications   

n.缓和( modification的名词复数 )；限制；更改；改变

参考例句：

• The engine was pulled apart for modifications and then reassembled. 发动机被拆开改型，然后再组装起来。 来自《简明英汉词典》
• The original plan had undergone fairly extensive modifications. 原计划已经作了相当大的修改。 来自《简明英汉词典》

38 retarded   

a.智力迟钝的，智力发育迟缓的

参考例句：

• The progression of the disease can be retarded by early surgery. 早期手术可以抑制病情的发展。
• He was so slow that many thought him mentally retarded. 他迟钝得很，许多人以为他智力低下。

39 attained   

（通常经过努力）实现( attain的过去式和过去分词 )； 达到； 获得； 达到（某年龄、水平、状况）

参考例句：

• She has attained the degree of Master of Arts. 她已获得文学硕士学位。
• Lu Hsun attained a high position in the republic of letters. 鲁迅在文坛上获得崇高的地位。

40 diffusion   

n.流布；普及；散漫

参考例句：

• The invention of printing helped the diffusion of learning.印刷术的发明有助于知识的传播。
• The effect of the diffusion capacitance can be troublesome.扩散电容会引起麻烦。