SYMMETRY IN TRANSPLANTED LIMBS 25 
which developed ulthnately into a left limb, the mirror image of 
the primary member, having been reversed from the original 
prospective asymmetry of the transplanted bud. 
^ . Heteropleural transplantations, dorsoventral orientation. Sixty 
operations were done in this series. For some unknown reason a 
very large proportion (twenty cases) died prematurely and six- 
teen of the survivors yielded only abortive limb buds, leaving 
only twenty-four available for consideration. Eight of these are 
recorded as imperfect, six produced reduplications to some degree, 
and nine, single limbs of reversed asymmetry. Several of the 
latter were somewhat defective and others showed slight redu- 
plications. Several cases which are exceptional will be consid- 
ered below. 
In the cases where single limbs arose, development took place 
in a manner fundamentally like that of the limb buds normally 
oriented {horn. dd.). As the buds grew out, they began to point 
in a posterior direction, and so continuing, developed into limbs 
in normal posture (fig. 27) . There was, however, less regularity 
than in the homopleural dorsodorsal group. The direction of 
pointing was not always dorsoposterior, as in the normal limb, 
but was in many cases inclined more ventrally. There are rec- 
ords of pointing in all of the positive experiments and in many 
of the negative. In only three cases is the direction recorded 
Fig. 27 Heterotopic transplantation of fore limb; right limb bud to left side 
inverted (het.dv.), Exp. Tr. E. 193. Preserved specimen killed twenty-four days 
after operation. X 10. 
Figs. 28 to 32 Heterotopic transplantation of fore limb; right limb bud 
to left side inverted (het.dv.), Exp. Tr. E. 217. N, normal left limb; TR, trans- 
planted limb; PR, primary member; DU, reduplicating member; 1 to 4, numbers 
of digits. 
Fig. 28 Dorsal view, five days after operation. 
Fig. 29 Lateral view, five days after operation. 
Fig. 30 Dorsal view, fifteen days after operation. 
Fig. 31 Lateral view of limbs, fifteen days after operation. 
Fig. 32 Limb showing beginning of reduplicating digits (Dl') on ventro- 
anterior border (from a free-hand sketch nineteen days after o]ieration). 
Figs. 33 and 34 Heterotopic transplantation {hel.dv.); right limb bud to left 
side. Exp. Tr. E. 163. Anomalous result. Primary member {PR) defective; 
reduplicating member {DU) reversed. Lateral and ventral aspects, respectively, 
drawn from specimen preserved thirty-nine days after oiKM'ution. X 10. 
