SYMMETRY IN TRANSPLANTED LIMBS 
107 
In this connection it is important to compare the orthotopic 
with the heterotopic operations in respect to the regulatory pro- 
cesses just considered. When the limb bud is implanted in ab- 
normal location, functional adaptation does not occur at all, the 
limbs rarely showing anj^ motor function whatever, unless placed 
close to the nomial position of the limb.^^^ 
Xow the records show (table 8) that the two harmonic combina- 
tions in the heterotopic series produced ten single harmonic limbs 
and twelve reduplications (44.4 and 55.6 per cent, respectively). 
TABLE S 
Comparison of heterotopic and orthotopic transplantations with reference to the 
relative number of single limbs and duplicities in the harmonic and 
disharmonic combinations 
HETEROTOPIC 
ORTHOTOPIC 
CHARACTER OF COMBIXATION 
Single 
Reduplicated 
Single 
Reduplicated 
Num- 
ber 
Per 
cent 
Num- 
ber 
Per 
cent 
Num- 
ber 
Per 
cent 
Num- 
ber 
Per 
cent 
Harmonic 
101 
19 
44.4 
86.4 
12 
3 
55.6 
13.6 
24 
22 
96.0 
3.4 
1 
573 
4 
Disharmonic 
96 6 
^ Excluding one anomalous case in which an error of record is probable. 
- Excluding five cases which became normal single limbs by development of 
the duplicate and resorption of the original bud, and ten cases which became 
normal by rotation. 
' Including five cases in which the original member was resorbed and the single 
normal limb arose from the reduplicating bud. 
In many of the latter, however, the doubling was but slight, in- 
vohdng onlj^ the digits. The two disharmonic combinations, on 
the other hand, produced nineteen single limbs (86.4 per cent) 
and three (13.6 per cent) redupUcations. The results obtained 
by Detwiler ('18), using much younger limb buds from embrj'os 
with open medullary folds, sustain the above results, as far as the 
haiTiionic group is concerned. There are eight cases of single 
lunbs and ten reduplications. In the dishamionic group, how- 
1'^ This has been subjected to a careful anal3'sis by Detwiler ('19, '20), who 
has shown that the failure to function is not due to lack of peripheral innervation 
so much as to the insufficient connections within the central nervous svstem. 
