SYMMETRY IN TRANSPLANTED LIMBS 21 
ences in the amount of rotation, etc., undergone during the 
later stages of development. 
- Histories of these cases are given in the appendix (p, 120). 
S. Heteropleural transplantations, dorsodorsal orientation. 
Twenty-eight experiments in this class have been made (table 1). 
Five of these died prematurely, and in twelve the tissue was 
either resorbed or failed to develop beyond the nodule stage. 
In one case^^ the bud developed into a stump about as long as the 
upper arm, but without digits. Two cases gave double limbs 
and eight developed into limbs which preserved their original 
prospective asymmetry. Two other cases may belong in this cate- 
gory, one in which the original orientation of the bud is recorded 
as uncertain^"^ and another^^ in which it is recorded as dorso ven- 
tral probably by mistake. 
In the development of the limb buds in this group twenty-one, 
in addition to the two doubtful cases just mentioned, are recorded 
at first as pointing in an anterodorsal direction, thus preserving 
their original tendency in this respect. In the eight cases in 
which the pointing was slight and in the five in which no definite 
pointing was observed the limbs were abortive or resorbed. 
In the eight cases where single limbs of the side of origin de- 
veloped they retained their posture, developing as nearly exact 
mirror images of the normal fore limb of the side to which they 
were transplanted (figs. 20 to 23). The elbow-joint points dorso- 
anteriorly, though varying somewhat, and the palm of the hand 
faces ventrally, medially, and anteriorly (figs. 24 and 25) . Indi- 
vidual cases show variations similar to those observed in the 
previous group. It is a striking fact that the general type of 
development is the same here in the heteropleural non-inverted 
buds as in the homopleural inverted bud, which shows that both 
the posture and the asymmetry of the limb depend upon some 
reaction between the bud and its new environment. (For case 
histories see p. 121.) 
The cases w^hich showed reduplications, but two in number, 
differ considerably from one another. In the first^^ growth was 
slow and the resulting limb short with irregular reduplications 
15 Tr. E. 118. " Tr. E. 117. i- Tr. E. 113. »8 Tr. E. 119. 
