IGUANIANS, 47 



animals are agile, light, and elegant in form ; they feed princi- 

 pally on insects, and prefer living prey. In summer they eat a 

 great deal ; but they can easily support a fast of several weeks 

 in summer, and four or five months in winter ; when held in cap- 

 tivity, they generally refuse to take food ; yet they bite at every 

 thing presented to them, and close their jaws with considerable 

 force. In our climate they pass the winter benumbed in holes, 

 and their movements are active in proportion as the temperature 

 is more elevated ; they love to warm themselves in the sun even 

 in midsummer, and they are often seen stretched on a stone bask- 

 ing in the sunshine. Many fables have been attached to these 

 animals ; some have pretended, without any reason, that they are 

 venomous ; others, without foundation, assert that they show a 

 true attachment for man, and give him warning when a serpent 

 is about to bite. A great many species are known. 



FAMILY OF IGUANIANS. 



27. The Saurians composing this family have very nearly the 

 same general form as the Lacertians: they also have a long tail, 

 free and unequal toes, &c.; but their tongue is fleshy, thick, not 

 extensile, and only notched at the end. 



28. The mouth presents the same modit^cations as the pre- 

 ceding family : sometimes they have teeth in the palate as well 

 as in both jaws ; sometimes there are only two ranges of teeth 

 in the upper jaw. 



29. Among the first are ranged the STELLIOS; they have the 

 tail surrounded by large scales, which are often spiny; the 

 AGAMIANS, in which the scales on the tail are imbricate t (that is, 

 having the scales lying over each other like shingles on a roof,) 

 and not verticillate, (that is, not arranged in a circle, around a 

 centre) ; the DRAGONS, &c. The last are distinguished from all 

 other reptiles by a species of wing formed on each side by a deep 

 fold of the skin. These appendices resemble the wings of a bat ; 

 but instead of being supported and set in motion by the extremi- 

 ties, they are altogether independent of them, and are sustained 

 by the first six false ribs which do not surround the abdomen, 

 but are extended horizontally in a straight line. The animal 

 uses these wings as a parachute, to sustain itself in the air when 

 it leaps from branch to branch ; but it cannot use them with 

 sufficient force to fly like a bat or a bird. These singular reptiles, 



27. What are the general characters of the Iguanians? 



28. What are the modifications met with in the mouth ? 



2!). What are Stcllios ? What are Agamians ? How are the Dragons 

 characterised ? 



