Evolutionists once commonly believed that all basic life forms which existed in our past multi-millions of years of evolution were rapidly repeated in the few months between conception and birth or hatching. Called the biogenetic law, this belief concluded that all embryos always rapidly pass through their evolutionary history, starting with the one cell stage, then in the case of humans developing into the fish stage, the reptile stage, the mammal stage, ape stage, and finally into a human-child stage. This theory, commonly explained as "ontogeny recapitulates phylogeny," was cited as a major proof of evolution for over a century. This paper also reviews many of the biogenetic law claims commonly used in pre 1960’s textbooks including the gill slits, tail, and yolk sac. Recent discoveries in the field of embryology and a reevaluation of the evidence for the theory has shown it is without foundation and now largely has been discarded by embryologists.