ANURA

also called Salientia one of the major extant orders of the class Amphibia. It includes the frogs and toads, which, because of their wide distribution, are known by most people around the world. The name frog is commonly applied to those forms with long legs and smooth, mucus-covered skins, toad being used for a variety of robust, short-legged anurans, especially those with rough skins. The name toad is applied so unevenly that one member of a family may be called a toad and a closely related member a frog. The familiar members of the family Bufonidae may be distinguished as true toads. In this article frog is applied generally to members of the Anura and toad to those for which it has traditionally been used. Edible frog (Rana esculenta). Frogs are used as teaching tools from grade school through college. One of the first biology lessons many children receive is through the rearing of the larvae, known as tadpoles or pollywogs, in science classes. Students become familiar with frog anatomy and embryology in biology courses. People in various parts of the world eat frog legs, and some kinds of toads are used in insect control. Certain South American Indians use the poisonous secretions of some kinds of frogs for poison arrows (see arrow-poison frog), and now biochemists are studying the possible medical uses of the constituents of the poison. The biologist interested in evolution finds a vast array of interesting, and often perplexing, problems in the study of frogs, a highly specialized group of amphibians. Additional reading Texts investigating various aspects or various species of the order include Bernd Fritzsch et al., The Evolution of the Amphibian Auditory System (1988), a review of vocalization and sound reception in frogs; Ronald Maxwell Savage, The Ecology and Life History of the Common Frog (Rana temporaria temporaria) (1961), a well-documented study of the biology of this species in England; William E. Duellman, The Hylid Frogs of Middle America, 2 vol. (1970), a detailed study of the taxonomy, distribution, life history, and ecology of the tree frogs of Mexico and Central America; H.W. Parker, A Monograph of the Frogs of the Family Microhylidae (1934, reprinted 1966), a thorough account of one of the most interesting families of frogs; Robert C. Stebbins, A Field Guide to Western Reptiles and Amphibians (1966), an excellent identification manual for frogs in the western United States; and Albert Hazen Wright and Anna Allen Wright, Handbook of Frogs and Toads of the United States and Canada, 3rd ed. (1949, reissued 1970), a well-documented account of North American frogs and toads with many black-and-white photographs. William E. Duellman