賴世雄高級(jí)美國(guó)英語(yǔ)教程Unit 5 Hot Animals around the World: Chameleons

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Every few months this program will feature an animal which has caught the eye of the world's public to become a favorite or "hot" animal. In the first of this unusual series, we will look at the chameleon, one of nature's strangest creatures.
Perhaps no other group of animals has caught mankind's imagination like reptiles. Among the several subclasses (or "orders" in biology) of reptiles are snakes and lizards, turtles and tortoises, crocodiles and alligators, and the tuatara, a marine lizard in New Zealand. The dinosaurs, too, belonged to the class of reptile. Was it a snake, lizard, or crocodile that caught the fancy of some Chinese in times gone by to create the dragon? A perennial theme, reptiles have been featured over the past ten years in box-office hits and bombs alike as dinosaurs (Jurassic Park and The lost World), crocodiles, and snakes (Anaconda). Though not nearly as large as these mighty reptiles, the lowly chameleon nonetheless has amazed countless generations with its special talents and skills.
What is a chameleon? Its unusual name fits this unusual animal perfectly, for it translates from the ancient Greek as "lion on the ground.' This is unexpected, since chameleons spend most of their time in trees, and as for looking like a lion, a chameleon looks like a ... well, a chameleon! No other animal in Nature's zoo looks quite as bizarre as they do. Where do they live? True chameleons are found only in the tropical forests and jungles of the Old World, and nearly half of its species live on the African island of Madagascar.
What's special about the chameleon? Plenty! From its tongue to its tail the chameleon offers a storehouse of specialties. The tongue of this modem-day dinosaur look-alike can be extended more than twice the length of its body. This type of tongue, also present in frogs and toads, is called an extensile tongue. The eyes of the chameleon are even more remarkable. Its eyes are turreted and can be moved independently so that it can view two different objects simultaneously! This comes in especially handy as it is tree dwelling. The chameleon can keep one eye on its prey and the other on its footing. Its head is often helmet-shaped, and some species have horn-like structures growing out of this scaly helmet.
The feet and tail of the chameleon are also special. Both are prehensile; that is, they are both perfectly adapted to their sylvan environment. The toes of the chameleon's feet are bunched into inside and outside groups of two or three to enable this reptile to grasp tree branches tightly. The chameleon can thus climb extraordinarily well while using its tail to grab objects for further balance.
The above inventory of natural selection specializations would be remarkable enough, but what really separates the chameleon from its fellow reptiles is the fact that its scales contain the ability to change color, Though many people think the chameleon can change its color at will and that it can blend into any color, these are misconceptions. In fact, chameleons can blend into many natural colors and even patterns, but they cannot do this at will. Instead, this happens naturally according to temperature, emotional state of the animal, and the triggering of certain hormones within its body.
It is hard to imagine an animal more interesting than the chameleon, with its weird appearance and special abilities. We should always remember, however, that these animals require their native habitat to flourish in, not zoos or individuals' terrariums. If you want your grandchildren to see this gift of nature, do not collect it as a pet. These natural treasures evolved over millions of years without mankind's help; they will continue to survive better if left alone.