SYMMETRY IN TRANSPLANTED LIMBS 
13 
(fig. 3). In the present paper the relation of the mirror plane 
to the long axis of the limb has not been taken into account for 
purposes of description, the relation only to the dorsopalmar and 
the radioulnar axes being stated; i.e., the degree of divergence 
of the two members is not taken into account. Thus, when the 
mirror plane is parallel to the radioulnar axis, the limb is said to 
A.DU 
Fig. 3 Diagram showing mode of reduplication. PR, primary limb; P.DU, 
posterior reduplicating member; A.DU, anterior reduplicating member; MP:{R), 
primary (radial) mirror plane; MPi(U), secondary (ulnar) mirror plane; 1 to 4, 
first to fourth digits, respectively. S, location of section shown in figure 4B. 
Dotted lines show the outlines of limbs as they w'ould have been had there been 
no coalescence. 
be mirrored in a palmar or a dorsal plane, according as the palms 
or the backs of the hand face one another; when the plane is 
parallel to the dorsopalmar axis, the mirroring is in a radial or 
an ulnar plane, according as the radial or ulnar borders of the 
limb face one another (fig. 4, A). Intermediate planes are de- 
scribed as radiodorsal, ulnopalmar, etc. (fig. 4, B). No attempt 
has been made for the present to measure accurately the angles 
of mirroring. It has been found, in agreement with Bateson, that 
