大学英语四级阅读题文章精读43

　　大学英语四级阅读题文章精读-43

　　Cryptic Coloring

　　Cryptic coloring is by far the commonest use of color in the struggle for existence. It is employed for the purpose of attack as well as of defense . The fact that the same method concealment, may be used both for attack and defense has been well explained by T.Belt who suggests as an illustration the rapidity of movement which is also made use of by both pursuer and pursued, which is similarly raised to a maximum in both by the gradual dying out of the slowest through a series of generations. Cryptic coloring is commonly associated with other aids in the struggle for life. Thus well-concealed mammals and birds, when discovered, will generally endeavor to escape by speed and will often attempt to defend themselves actively. On the other hand, small animals which have no means of active defense, such as large, numbers of insects, frequently depend upon concealment alone. Protective resemblance is far commoner among animals than aggressive resemblance, in correspondence with the fact that predaceous forms are as a rule much larger and much less numerous than their prey. In the case of insectivorous Vertebrata and their prey such differences exist in an exaggerated form. Cryptic coloring, whether used for defense of attack, may be either general or special. In general resemblance the animal, in consequence of its coloring, produces the same effect as its environment, but the conditions do not require any special adaptation of shape and outline. General resemblance is especially common among the animal inhabiting some uniformly colored expanse of the earths surface, such as an ocean or a desert. In the former, animals of all shapes are frequently protected by their transparent blue color, on the latter, equally diverse forms are defended by their sandy appearance. The effect of a uniform appearance may be produced by a combination of tints in startling contrast. Thus the black and white stripes of the zebra blend together at a little distance, and their proportion is such as exactly to match the pale tint which arid ground possesses when seen by moonlight. Special resemblance is far commoner than general and is the form which is usually met with on the diversified surface of the earth, on the shores, and in shallow water, as well as on the floating masses of algae on the surface of the ocean, such as the Sargasso Sea. In these environments the cryptic coloring of animals is usually aided by special modifications of shape, and by the instinct which leads them to assume particular attitudes. Complete stillness and the assumption of a certain attitude play an essential part in general resemblance on land; but in special resemblance the attitude is often highly specialized, and perhaps more important than any other element in the complex method by which concealment is effected. In special resemblance the combination of coloring, shape, and attitude is such as to produce a more or less exact resemblance to some one of the objects in the environment, such as a leaf of twig, a patch of lichen, a flake of bark. In all cases the resemblance is to some object which is of no interest to the enemy or prey respectively. The animal is not hidden from view by becoming indistinguishable from its background as in the case of general resemblance, but it is mistaken for some well-know object.

　　In seeking the interpretation of these most interesting and elaborate adaptations, attempts have been made along two lines. The first seeks to explain the effect as a result of the direct influence of the environment upon the individual , or by the inherited effects of efforts and the use and disuse of parts . The second believes that natural selection produced the result and afterwards maintained it by the survival of the best concealed in each generation. The former suggestion breaks down when the complex nature of numerous special resemblances is appreciated. Thus the arrangement of colors of many kinds into an appropriate pattern requires the cooperation of a suitable shape and the rigidly exact adoption of a certain elaborate attitude. The latter is instinctive and thus depends on the central nervous system. The cryptic effect is due to the exact cooperation of all these factors; and in the present state of science, the only possible hole of an interpretation lies in the theory of natural selection, which can accumulate any and every variation which tends toward survival. A few of the chief types of methods by which concealment is effected may be briefly described. The colors of large numbers of vertebrate animals are darkest on the back and become gradually lighter on the sides, passing into white on the belly. Abbot H. Thayer has suggested that this gradation obliterates the appearance of solidity, which is due to shadow. The color harmony, which is also essential to concealment, is produced because the back is of the same tint as the environment , bathed in the cold blue-white of the sky, while the belly, being cold blue-white and bathed in shadow and yellow earth reflections produces the same effects. This method of neutralizing shadow for the purpose of concealment by increased lightness of tint was first suggested by E.B.Poulton in the case of a larva and a pupa, but he did not appreciate the great importance of the principle. In an analogous method an animal in front of a background of dark shadow may have part of its body obliterated by the existence of a dark tint, the remainder resembling, e.g., a part of a leaf. This method of rendering invisible any part which would interfere with the resemblance is well know in mimicry.

　　1. The black and white stripes of the zebra are most useful form

　　[A]. hunters. [B]. nocturnal predators

　　[C]. lions and tigers. [C]. insectivorous Vertrbrata

　　2. Aggressive resemblance occurs when

　　[A]. a predaceous attitude is assumed.

　　[B]. special resemblance is utilized.

　　[C]. an animal relies on speed.

　　[D]. an animal blends in with its background.

　　3. Special resemblance differs from general resemblance in that the animal relies on

　　[A]. its ability to frighten its adversary. [B]. speed.

　　[C]. its ability to assume an attitude. [D]. mistaken identify

　　4. The title below that best expresses the ides of this passage is

　　[A]. Cryptic coloration for Protection. [B]. How Animals Survive.

　　[C]. The uses of Mimicry in Nature. [D]. Resemblances of Animals.

　　5. Of the following which is the least common?

　　[A]. protective resemblance. [B]. General resemblance.

　　[C]. Aggressive resemblance. [D]. Special resemblance.

　　Vocabulary

　　1. cryptic 隐藏的，保护的

　　cryptic coloring 保护色，隐藏色

　　2. predaceous 食肉的，捕食其他动物的。

　　3. vertebrate 脊椎动物门

　　4. tint 色泽，色彩

　　5. zebra 斑马

　　6. Sargasso 果本马尾藻

　　7. twig 嫩枝

　　8. lichen 地衣

　　9. flake 一片

　　10. gradation 等级，层次，分等

　　11. obliterate 涂抹，擦去，使消失

　　12. larva 幼虫，幼体

　　13. pupa 蛹

　　14. mimicry 模仿，拟态

　　15. nocturnal 夜间发生的，夜出的

　　16. insectivorous 食虫的

　　17. procryptic 有保护色的，保护性的

　　难句译注

　　1. the rapidity of movement which is also made use of by both pursuer and pursued, which is similarly raised to a maximum in both by the gradual dying out of the slowest through a series of generations.

　　[参考译文] 追捕动物和被追的动物也利用快速的动作。这种快速的运动同样是通过几代更迭，逐渐消除了慢速，而发展到快速顶峰。

　　2. Protective resemblance is far commoner among animals than aggressive resemblance, in correspondence with the fact that predaceous forms are as a rule much larger and much less numerous than their prey.

　　[参考译文] 保护性模仿远比侵犯行模仿要普遍得多，这是和下述的情况想配合的：食肉的动物，按惯律总是比他们捕食的对象要大而且多得多。

　　3. The effect of a uniform appearance may be produced by a combination of tints in startling contrast.

　　[参考译文] 在惊人的对比中，色泽的综合可能产生外形一致的效果。

　　4. their proportion is such as exactly to match the pale tint which arid ground possesses when seen by moonlight.

　　[参考译文] 比例正好和在月光下观看贫瘠土地所具有的苍白色泽相吻合。

　　5. In these environments the cryptic coloring of animals is usually aided by special modifications of shape, and by the instinct which leads them to assume particular attitudes.

　　[参考译文] 在这些环境中，动物的保护色常常得到特定的形状变化和本能的协作，这种本能会使动物采取特定的姿势。

　　6. Complete stillness and the assumption of a certain attitude play an essential part in general resemblance on land; but in special resemblance the attitude is often highly specialized

　　[参考译文] 绝对静态和采取一般姿势在陆地的一般模仿中起很大作用，而在专门模仿中，姿势常常是高度专门化的。

　　7. Thus the arrangement of colors of many kinds into an appropriate pattern requires the cooperation of a suitable shape and the rigidly exact adoption of a certain elaborate attitude.

　　[参考译文] 因此许多类颜色排列成恰当的模式/形式，要求把合适的外形和严格的采用一定的精心设计的姿势相结合。

　　8. The cryptic effect is due to the exact cooperation of all these factors; and in the present state of science, the only possible hole of an interpretation lies in the theory of natural selection, which can accumulate any and every variation which tends toward survival.

　　[参考译文] 保护效果是由于所以这些因素确切合作而形成。根据目前科学水平，唯一的解释就是自然选择理论，它可以累积要生存的各种变异/变种。

　　写作方法与文章大意

　　文章以一般到具体的协作和分类方式写作，第一段点出生物界生存竞争中最常用的一种颜色是保护色，保护色可分为两类：进犯型和防卫型。一般是防御性保护色多于进攻型。而两种类型都可归纳为一般性模仿和专门模仿。居住在单一色泽的地方的动物，如海洋或沙漠，常采用模仿性保护色 如透明的绿色，土色等，而特定摸刚的动物则栖息在多样性的地方，如海岸，浅水，海洋表面等。特定模仿还需要有改变形状姿势之协作，使其看起来像客观环境中的某物，某种身份mistaken identify.

　　第二段涉及有关模仿性的解释的探索，结果为二。一种观点是环境直接影响的结果。第二种是自然选择的结果。当人们理解了许多特定模仿的复杂特性时，第一种解释就不能成立了。这说明保护效果是一切因素 合适的外形和某种精心设计的姿势等 合作而成。按现在科学水平来解释，只能归之 自然选择 理论，然后是用具体例子来证实。

　　答案祥解

　　1. B. 夜间活动的食肉动物。见难句译注4，斑马的黑白相间颜色的比例正好和月光下所见的贫瘠土地的苍白的色泽相吻合。当然能保护斑马夜间免遭这些食肉动物的袭击。

　　A. 捕获者。 C. 狮子和老虎。 D. 食虫的脊椎动物

　　2. A. 在装成捕食其他动物的姿势时。

　　B. 应该专门模仿。 C. 动物依赖速度。 D. 动物和背景混在一起。

　　3. D. 搞错/认错了动物。见第一段最后一句话，它不像一般模仿那样，通过动物和背景难以辨别从而从视觉中隐藏起来，它是被误认为某种着名动物。

　　A. 用以吓走它的对手的能力。 B. 速度。 C. 采用某种姿势的能力。

　　4. C. 自然界模拟的运动。文章一开始就点命保护色迄今为止生存斗争中最常用的一种颜色，常用于进攻和防卫。保护色常和其他措施相配合，首先提到速度，见难句译注 1。然后讲到保护色分类，一般和特殊模拟/模仿。第二段解释或说明模拟适应性。第一种解释为环境使然/影响。第二种认为是自然界选择之结果。

　　A. 为了保卫的保护色。 B. 动物是如何存活下来。 D. 动物之模仿性。

　　5. C. 进攻性模仿。见难句译注2。

　　A. 保护色模仿。 B. 一般性模仿。 D. 专项模仿