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IGUANA

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Originally appearing in Volume V14, Page 296 of the 1911 Encyclopedia Britannica.
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IGUANA , systematically Iguanidae (See also:

Spanish quivalent of Carib iwana), a See also:family of pleurodont lizards, comprising about 50 genera and 300 See also:species. With three exceptions, all the genera of this extensive family belong to the New See also:World, being specially characteristic of the Neotropical region, where they occur as far See also:south as See also:Patagonia, while extending northward into the warmer parts of the Nearctic regions as far as See also:California and See also:British See also:Columbia. The exceptional genera are Brachylophus in the See also:Fiji Islands, Hoplurus and Chalarodon in See also:Madagascar. The iguanas are characterized by the See also:peculiar See also:form of their See also:teeth, these being See also:round at the See also:root and blade-like, with serrated edges towards the tip, resembling in this respect the gigantic See also:extinct reptile See also:Iguanodon. The typical forms belonging to this family are distinguished by the large See also:dewlap or pouch situated beneath the See also:head and See also:neck, and by the See also:crest, composed of slender elongated scales, which extends in gradually diminishing height from the nape of the neck to the extremity of the tail. The latter See also:organ is very See also:long, slender and compressed. The See also:tongue is generally See also:short and not deeply divided at its extremity, nor is its See also:base retracted into a sheath; it is always moist and covered with a glutinous secretion. The prevailing See also:colour of the iguanas is See also:green; and, as the See also:majority of them are arboreal in their habits, such colouring is generally regarded as See also:pro- tective. Those on the other See also:hand which reside on the ground have much duller, although as a See also:rule equally protective hues. Some iguanas, however (e.g. Anolis carolinensis), possess, to an extent only exceeded by the See also:chameleon, the See also:power of changing their See also:colours, their brilliant green becoming transformed under the See also:influence of fear or irritation, into more sombre hues and even into See also:black. They differ greatly in See also:size, from a few inches to several feet in length.

One of the largest and most widely distributed is the See also:

common iguana (Iguana tuberculata), which occurs in the tropical parts of Central and South See also:America and the See also:West Indies, with the closely allied I. rhinolophus. It attains a length of 6 ft., weighing then perhaps 30 lb, and is of a greenish colour, occasionally mixed with See also:brown, while the tail is surrounded with alternate rings of those colours. Its See also:food consists of See also:vegetable substances, mostly leaves, which it obtains from the See also:forest trees among whose branches it lives and in the hollows of which it deposits its eggs. These are of an oblong shape about 4 in. in length, and are said by travellers to be very pleasant eating, especially when taken raw, and mixed with See also:farina. They are timid, defenceless animals, depending for safety on the See also:comparative inaccessibility of their arboreal haunts, and their protective colouring, which is rendered even more effective by their remaining still on the approach of danger. But the favourite resorts of the iguana are trees which overhang the See also:water, into which they let themselves fall with a splash, whatever the height of the See also:tree, and then swim away, or hide at the bottom for many minutes. Otherwise they exhibit few signs of See also:animal intelligence. " The iguana," says H. W. See also:Bates (The Naturalist on the See also:Amazons), " is one of the stupidest animals I ever met. The one I caught dropped helplessly from a tree just ahead of me; it turned round for a moment to have an idiotic stare at the intruder and then set off See also:running along the path.

End of Article: IGUANA

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