Studies in Embryonic and Larval Development in Amphibia

Among the Amphibia there are numerous examples of the suppression to a varying extent of a larval stage in the life-history. In such instances the animal is freed by various means from the necessity of passing its early phases of development in open water. This evolutionary trend has nowhere proceeded further than in the Anuran genus Eleutherodactylus, which is distributed through the Caribbean and the adjacent mainlands. In Eleutherodactylus, development is direct and wholly embryonic, and many larval features have been suppressed. In 1871 was published the first description of a West Indian frog which laid eggs in air, and from which young frogs with fully formed limbs were hatched (Bello y Espinosa, 1871). Since that time some twenty papers have been published on the embryology of different species of the genus, mainly in recent years by Dr. W. Gardner Lynn and his collaborators.