A preliminary investigation into the effect of thyroid hormones on the metamorphic changes in Meckel's cartilage in Xenopus laevis.

The effects of short-term dosage with thyroid powder on the metamorphic changes in Meckel's cartilage in Xenopus laevis are described. The Lag phase of development appears to be by-passed, and the usual sequential arrangement of the Division and Synthesis phases is disrupted, the processes of normal metamorphic changes being considerably accelerated.