SYMMETRY IN TRANSPLANTED LIMBS 77 
The double limbs are of various degree and kind. The least 
involved is one in which only the first digit is doubled. ^^ In this 
individual the ventral half of the limb was replaced by a ventral 
half of the opposite side, and in all probability very little limb 
material was actually transplanted, since, in the embryo from 
which the graft was taken, the operated limb developed almost 
as rapidly as the normal. In five other cases'^'^ (fig. 127) the whole 
hand is involved, with indications that in three of these at least*^ 
the internal reduplication extends farther proxmially. In two 
cases the fore arm and hand^* (figs. 128 and 129) are externally 
double, and in one,*^^ which was not fully developed when pre- 
served, doubling would probably have shown from near the 
shoulder down. In two of the individuals^" there are secondary 
reduplications. In the two anomalous cases'-'^ (figs. 131 and 132) 
there are two entirely separate limbs. 
Histories are given on page 134, Unfortunately, external 
observation does not always reveal the ]"elations of each of the 
two halves of the bud to the developing members. 
21. Heteropleural transplantations, dorsoventral orientation. 
Out of twenty-two successful experiments in this group nineteen 
resulted in the development of normal limbs (fig. 133), which is 
according to rule, and only three gave rise to reduplications (fig. 
134). Two of the latter^^ involved only the radial digits, in 
which palmar reduplication was present, the limbs being other- 
wise normal. In the remaining one a bifurcated appendage 
arose, but the dorsal branch remained merely as a spur attached 
to the main limb, which was normal though undersized and with 
slight syndactyly. 
In one case,^^ which has been classed as normal, a filamentous 
appendage probably not a limb, developed a short distance ven- 
tral to the main limb, which was normal though slightly shorter. 
85 H. R. E. 30. so H. R. E. 21 and 47. 
»« H. R. E. 1, 15, 46, 47, and 48. " H. R. E. 9 and 20. 
" H. R. E. 15, 46, and 47. ^^ H. R. E. 10 and 16. 
«8 H. R. E. 5 and 21. 93 h. R. E. 12. 
8" H R. E. 28 
