Ecological Studies of the Arthropods Associated with Certain Decaying Materials in Four Habitats

pine barrens may be a limiting factor in the distribution of anurans. Rana virgatipes and Hyla andersoni embryos tolerate more strongly acid solutions than any of the other species tested. Rana palustris and Acris g. crepitans have the least tolerance to such conditions and these species are practically absent from unaltered pine barrens habitats. Seven of the eleven species tested require bog water or tap water acidified with hydrocloric acid at at a pH of 4.1 or higher for normal development. 5. Hyla c. crucifer is capable of spawning successfully in bog water at a pH of 4.2-4.5. Pseud-acris is able to spawn in bog water at pH 4.7, or perhaps even lower. 6. We recognize the probability that additional factors are involved in limiting the distribution of local anurans in the barrens. In fact, it is likely that none of the species is either restricted to or excluded from the pine barrens by the pH factor alone. It is possible that for some species, however , pH may have some significance since many of the bogs and swamps are too acid for normal embryonic development to occur. Other physical or chemical factors in the bog water, at present unknown, may have deleterious effects on the embryos , the larvae, or on the fertilization process itself.