the region of the bud, and there was no mesenchym near by to account for the disappearance of the bud except the mesenchymatic rudiment of the ear capsule. It seems, as if here we almost directly perceive, how the limb mesenchym is turned to capsule-mesenchym.
It still remains to show why a redetermination has taken place in a certain part of my larvae, and in another it didn't. Redetermination has taken place only in cases operated in 1925. In 1924 no redetermination was to be abserved. In the latter year the larvae were chiefly operated in stage III; in 1925 in stage II and I. It may be possible, that in an earlier stage the determination is not so strong and may be more easily changed, but this does not explain everything, so I think, that there must be another cause for the different results obtained in my two experimental series. The redetermination itself needs time. It a larva developes more slowly, the ear vesicle has more time to influence the material of the lateral plate. And in fact, the operated larvae have developed in 1925 more slowly, than in 1924. The average time, that elapsed between the operation and the fixation in 1924 was 30 days, in 1925 it was 51 day, the stage of fixation being in no way older in 1925 than in 1924.
