http://worms.zoology.wisc.edu/frogs/welcome.html

This tutorial is part of an ongoing project designed to implement multimedia and computer-based learning materials in the university undergraduate classroom. The materials presented here are NOT designed to replace either hard work outside of class wrestling with the dynamic nature of embryonic development, nor are they meant as a substitute for "wet lab" experience using a real microscope and real embryos. Instead, this tutorial is meant to supplement the presentation of standard videotape, laser video, digitized video and animation sequences in the traditional lecture period.