>The experiments to be discussed next centre around the following problems : Which factors are instrumental in the process of determination? How is the determination of the medullary plate, of the eye, of the balancer, accomplished? There is no one answer to these questions. Different agents are at work in each instance, and each primordium requires a special analysis.
2. Failure of Lens Formation after extripation of the eye Primordium in the Medullary Plate.
3. Failure of Lens Formation after Extirpation of the Optic Vesicle in early tail-bud stages.
4. The Organizer Experiment : Transplantation of the Upper Lip of the Blastopore.
5. Implantation of the Organizer in the Blastocoel
