Figure 5.

(A)−(E) Supernumerary limb structure after 180^o rotation. (A) Supernumerary with the first three digits of normal structure and the fourth of mirror‐imaged structure. The abnormality in the fourth digit is caused by the contribution of ventral GFP cells but it is clear that there is also a large contribution of GFP cells all across the limb which does not change the pattern of the other three digits. (B) Close‐up of digit 3 of the supernumerary in (A) showing a very significant contribution of GFP cells to the muscles which does not alter the pattern. (C) A digit of a supernumerary which is composed of GFP dorsal tissues and white ventral tissues yet the cartilage is anterior white and posterior GFP. A white line marks the GFP/stump tissue border in the cartilage which is at right angles to the rest of the mesodermal and epidermal tissues. (D) A complementary example of the composition of a supernumerary digit where the dorsal half of the cartilage is GFP and the ventral half is white. (E) A supernumerary digit which is double ventral caused by an influx of GFP cells to the upper part of the digit in which the GFP perichondrium encircles the cartilage made up of white cells. (F)−(I) Dedifferentiated cells from muscle grafts are drawn to the anterior side of the blastema in every case. (F) Tail skeletal muscle stream of GFP cells going to the anterior side from its dorsal grafted position. (G) Stream of GFP cells from a graft of cardiac atrium moving to the apical cap and doing a U‐turn. (H) Stream of GFP cells derived from a cardiac ventricle graft moving to digit 1 of the regenerate. (I) Stream of GFP cells from tail skeletal muscle moving to the digit 1 position.