用英文介绍动物身上的科学如鳄鱼为什么流泪？兔子的眼睛为什么是红的？、、、、、、~-~ （In English.)#_#~~谢谢！

用英文介绍动物身上的科学如鳄鱼为什么流泪？兔子的眼睛为什么是红的？、、、、、、~-~ （In English.)#_#~~谢谢！
用英文介绍动物身上的科学
如鳄鱼为什么流泪？兔子的眼睛为什么是红的？、、、、、、
~-~ （In English.)#_#~~谢谢！

用英文介绍动物身上的科学如鳄鱼为什么流泪？兔子的眼睛为什么是红的？、、、、、、~-~ （In English.)#_#~~谢谢！
(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 (aggressive resemblance or anticryptic coloring ) as well as of defense (protective resemblance or procryptic coloring ). 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 earth’s 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 (G.L.L.Buffon), or by the inherited effects of efforts and the use and disuse of parts (J.B.P.Lamarck). 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 (e. g. earth), 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.
这篇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（进攻）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（特定）模仿.居住（栖息）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.
希望对你有用.