THE life history of various plants and animals frequently offer considerable assistance in determining the phylogenetic positions of the members of a group of related species. Courtship patterns, for instance, have helped in the determination of phylogenetic relations in salamanders (Noble, 1925a) where these patterns show a rather clear-cut sequence which appears to follow the morphological phylogenetic steps. One type of phylogenetic tendency that may be found in animals occurs when several different morphological groups appear to have evolved independently along parallel lines. Some of the difficulties in the interpretation of the phylogeny of the frogs and toads are the result of parallelism and convergence exhibited by both morphological and life-history characteristics. Several aspects of the general subject of amphibian life history have been reviewed previously by Sampson (1900, breeding and development), Noble (1925b, 1927, life history), Lutz (1947, 1948, development) and Jameson (1955, courtship and mating behavior). This discussion is intended to demonstrate selected aspects of the variation and parallelism shown in salientian life history and to emphasize that these occur in independent phylogenetic lines. Four parallel tendencies appear in the life history of the salientians: (1) the increasing role of the female in courtship, (2) the opposition of the cloacas during oviposition, (3) the transfer of much or all of the courtship and spawning behavior from the aquatic to terrestrial situations, (4) the increasing care of the eggs. The more primitive breeding condition may be that found in the purely aquatic breeders such as Bombina (Liu, 1950), Xenopus (Bles, 1905), Rhinophrynus (Stuart, 1935), Scaphiopus (Bragg, 1944, 1945), Bufo (Aronson, 1944) and most Rana (Noble and Aronson, 1942). In these the male calls, thus attracting the female to the breeding site. The calls serve a very important role in the courtship of most frogs and toads, both in spacing out the males (Martof, 1953) and in attracting the females. The male Ascaphus (Noble and Putnam, 1931), lacking a voice, is forced to seek out the passive female. Males of some Scaphiopus will pursue the female as soon as she is sighted, while males of other Scaphiopus, Scutiger (Liu, 1950), Bufo, Rana, Rhacophorus (Liu, 1950) and Syrrhophus (Jameson, 1954) call until the female approaches rather near, and then pursue her to achieve amplexus. During the approach or pursuit of the female several frogs have special calls, and Syrrhophus, a terrestrial breeder stimulates the female by the use of his hind legs. Males of Microhyla (Jameson, 1955) and some Scaphiopus and Hyla (Smith, 1940) will call until touched by the female, while males of other Hyla must be almost attacked by the female before amplexus (Noble and Noble, 1923). In Dendrobates the females pursue the actively moving, calling, male (Dunn, 1941). Thus we can trace an increasing-role of the female in the courtship pattern which may have phyletic significance. Most of the frogs that are generally considered primitive (Bombina, Rhinophrynus, Xenopus, Scaphiopus and Scutiger) have amplexus in the pelvic regions but Ascaphus, Alytes (De L'Isle de Dreneuf, 1876) and Pipa (Bartlett, 1896) have modified their amplexus to adjust for specialized types of oviposition and care of the eggs. Ascaphus has an intromittent organ that assists in fertilization