[The induction capacity of dorsal lips tested by xenoplastic operations]

Xenoplastic implantation of dorsal lips according to the insertion and sandwich technique shows the following results using the two speciesXenopus laevis andAmbystoma mexicanum: 1. The percentage frequency of fore head and hind head inductions is in general higher than that of mesodermal inductions. 2. Comparing the two operational techniques it is demonstrated that fore head and chorda are more frequently induced in sandwiches than with the insertion method in both combinations XU→AW and AU→XW. 3. Independent of the implantation technique the blastoporal lip of Xenopus induces in Ambystoma host tissue more frequently noses, ear vesicles, hind brain and neural tubes than doesAmbystoma dorsal lip inXenopus host tissue.