A view of amphibian embryology during the last century

Having started working in the field of amphibian embryology over 50 years ago, I make some comments about the changes that seem to me to have taken place in this field over this period. Over the period 1885 to 1960, much of the highly regarded experimental embryology was conducted on amphibian eggs and embryos. Indeed, much of this work was conducted in Germany and Switzerland using eggs and embryos of European newts (salamanders) and frogs of the Rana group. Xenopus started to be used extensively after the 1950s because eggs and embryos could be obtained throughout the year by hormone injection and because sexually mature animals could be raised from an egg within one year. Since the 1960s, publications using Xenopus have exceeded those using other amphibian species by 100-fold. This short commentary highlights some of the major advances attributable to embryological work with Amphibia and exemplifies these advances by reference to those who have made conspicuous contributions in this area.