SYMMETRY IN TRANSPLANTED LIMBS 31 
of the operation as such on the development of the hmb. A fore 
Hmb bud is carefully excised and either replaced in the same 
wound or else engrafted in normal position in another embryo 
from which the limb bud had been previously removed. 
Only nine individuals were operated upon, in all of which the 
wounds were carefully cleaned. Normal limbs developed in all 
cases, though they were slightly retarded in the earlier stages of 
development in comparison with the unoperated limb of the 
opposite side. In six of the cases the pronephros was removed 
and in the other three it was left in. No difference was noted 
between the two sets. It may be safely concluded that the 
effect of the operation itself upon normal development is prac- 
tically negligible. 
8. Homopleural transplantations, dorsoventral orientation. In 
some of the cases of this series, as in the last, the limb bud was 
simply lifted and replaced after rotation through 180°. In the 
others the wound bed was first prepared in one embiyo and the 
bud taken from another. The latter method is preferable and 
it was employed in all the later experiments. 
The total number of experiments is one hundred and four, of 
which sixty-one were with cleaned wounds of proper size. The 
latter will be considered first, since the conditions of experimenta- 
tion are more definitely known arid there can be no doubt that 
the limbs were derived exclusively from the transplanted tissue. 
Leaving out of consideration the twenty-three cases which died 
prematurely or gave rise merely to abortive or rudimentary 
limbs, there are thirty-eight cases which yielded positive results, 
as recorded in table 2A, The single limbs are in the minority 
and are of two kinds, reversed and non-reversed. The most re- 
markable case^"* (history on p. 124), which really gives the clue 
to the interpretation of the experiments of this group, is the one 
in which a limb of reversed asymmetry developed, a right limb 
on the left side, perfectly normal in form, function, and posture, 
as far as the last is possible on the wrong side of the body (figs. 
35 to 41 j. The shoulder-girdle of this limb is also reversed and 
3^ I. E. 64. 
THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 32, NO. 1 
