A test of the predictions of the boundary model regarding supernumerary limb structure.

The model proposed in the preceding paper (Meinhardt, 1983) makes specific predictions about the handedness of supernumerary limbs generated after 180 degrees rotation of blastemas. These predictions are tested here by re-examining, in detail, the structure of 100 of these supernumeraries. Of the four predictions, only one was found not to hold. The other three are remarkably precise in their predictions and fit perfectly with the data. A possible reason for the failure of this one prediction is suggested.