TRANSPLANTATION OF LIMBS IN AMBLYSTOMA Tal 
the tenth or eleventh day they were almost as large as the trans- 
planted rudiment. They then began to undergo reduction in 
size, but did not finally disappear until eighteen to twenty days 
after the operation. 
All regenerating nodules of cells which appeared in the series 
AS4 and AS5 completely regenerated into a normal appendage 
at the original site. 
It is readily seen, therefore, from these observations that there 
is an inhibitory influence of the transplanted limb upon the 
unremoved portion of the rudiment which attempts to regenerate, 
so that the more remote the transplanted limb bud becomes, 
the longer the time required for total disappearance of the re- 
generating nodule of cells. Since no sections of these cell nodules 
were made and since it could not be ascertained from external 
observations, it was impossible to say whether the regenerating 
cells were actually drawn over into the transplanted limb bud 
or whether, lacking the necessary stimulus for growth, they 
underwent atrophy and were resorbed. However, no matter 
what influence the limb bud exerts on these regenerating nodules, 
it is no longer manifested when the transplanted bud is removed 
the distance of four segments, for in the series AS4 and ASS 
when regenerating nodules of cells appeared they always com- 
pletely regenerated an appendage. 
DISCUSSION 
When the anterior limb of Amblystoma punctatum is excised 
and reimplanted to the same embryo at distances ranging from 
one to seven segments posterior to the normal position (auto- 
plastic transplantation), corresponding decrease in the function 
of such limbs occurs as they are implanted more and more remote 
from the normal situation. A position is finally reached (six 
segments posterior to the normal) in which all limbs exhibit 
imperfect function, there being no cases with perfect adaptive 
movements (table la and fig. 9). This gradual decrease in the 
function of the limbs seems to be directly correlated with the 
segmental nerve supply (table 2), the function of the lmbs 
