SYMMETRY IN TRANSPLANTED LIMBS 
9 
ihet.dd.) remains as it was. The limbs which develop here are 
not primarih' in harmony- with their surroundings, so that these 
combinations ha\'e been termed disharmonic. 
Fig. 2 Diagram showing the results of the four operations, heterotopic or 
orthotopic, represented as on the right side of the embryo. The circles indicate 
the transplanted limb buds, the letters having the same significance as in figure 1. 
Thus the two upper figures in the diagram represent homopleural, and the two 
lower ones heteropleural transplantations. The two on the left show the trans- 
planted bud in upright (dorsodorsal) orientation while the two on the left are 
inverted (dorsoventral). The limbs \Vhich develop are shown in profile, the ulnar 
border being uppermost (dorsal) in all which actually develop. A heavy outline 
indicates the primary member, a light outline the reduplicating one. It is to 
be noted, however, that the latter develop in by no means all cases, while the 
former may be resorbed in the heteropleural dorsoventral combination, leaving 
only the reduplicating member present. The broken outlines show the posture 
that the limb would have assumed, had it developed as a self-differentiating mem- 
ber totally independent of the influence of its surroundings. 
The transplanted limb bud is a flattened disc of tissue, and it 
is theoretically possible to make eight further combinations by 
placing the medial surface of the graft corresponding to the lateral 
surface of the embryo. This is impracticable, however, because 
