SYMMETRY IN TRANSPLANTED LIMBS 35 
which case its asymmetry is reversed (figs. 36 to 39), just as in 
the corresponding class of heterotopic transplantations, or it 
gradually rotates towards its normal position while retaining its 
original prospective asymmetry (figs. 56 to 59). In the former 
alternative duplicate limbs are nearly always formed. Only in 
the one case, referred to above, did a perfect single limb arise. 
In the other alternative single limbs usually arise, though some 
of the cases of reduplication certainly belong to this group. 
In the duplicities belonging to the first group the original limb 
bud continues to grow in an anterior direction and ultimately 
becomes a reversed limb. After a time a reduplicating bud 
appears on the posterior border of the original bud (fig. 44) and 
in the clearer cases grows into a homopleural limb in approxi- 
mately normal posture (figs. 45 to 48). The original bud becomes 
a reversed limb which, together with the reduplicating member, 
may form an almost symmetrical complex. 
Twenty-four of the thirty-one^^ cases of reduplicated limbs are 
probably of this type. Fifteen are certainly so," and in three 
others^^ that are very similar all that is lacking to place them 
unequivocally in this group is a definite observation as to which 
bud was the primary one; six more cases^** may also be inter- 
preted in the same manner, though they are not sufficiently clear 
to insure that this is the only possible interpretation. 
The degree of reduplication varies here, as in the other groups 
of experiments, from the condition where almost the whole arm 
is involved to that in which the hand is only partly double. In 
three cases^° the anterior bud was much reduced (p. 49), the 
posterior bud becoming a somewhat irregular homopleural limb. 
In eleven cases there is only one reduplicating appendage, which 
is always posterior to the primary (figs. 43 to 48), while in the 
remaining twelve^^ there are evidences of further doubling, usu- 
=^ Four cases are considered here which are not included in the tabulation on 
account of the fact that the wound was only 3 somites in diameter (I. E. 39, 41, 
44 and 45). 
" I. E. 48, 60, 62, 63, 66, 72, 74, 75, 81, 85, 87, 89, 91, 92, and 96. 
's I. E. 44, 45, and 52. 
39 1. E. 39, 68, 70, 93, 100, 102. 
" I. E. 92, 93, 100. 
« I. E. 39, 45, 62, 63, 66, 72, 75, 81, 85, 87, 91, and 93. 
