134 S. R. DETWILER 
Series AS2. In this series of experiments the limb rudiment 
was excised and reimplanted the distance of two segments poste- 
rior to the normal position, so that the rudiment which originally 
extended from the anterior border of the third myotome to the 
posterior border of the fifth, now occupies a region from the 
anterior border of the fifth myotome to the posterior border of 
the seventh; and this rudiment, subsequent to its convergence 
into the definitive limb bud, centers ventral to the sixth myotome 
instead of the fourth, as in the normal situation (fig. 5). The 
denuded area underneath the third and fourth somites was 
covered by ectoderm taken from another individual. 
In eighteen positive experiments of this series there occurred 
only one in which a reduplicated appendage developed. The 
remainder gave rise to normal limbs (table 1). The results of 
the study of the behavior of these limbs showed that, although 
all were capable of movements, 16 per cent showed restricted 
movements. The remainder functioned normally (table 1 and 
fig. 9). 
Two individual cases of this series, viz., AS2; and AS2,. (pre- 
served, respectively, fifty-six and fifty-two days after the oper- 
ation, were sectioned and studied. The heterotopic limbs in 
both cases were found to receive the normal segmental nerve 
contribution, the plexus in each case being derived from the 
third, fourth, and fifth nerves (table 2). Such being the case, 
it is highly probable that all of the series AS1 were likewise 
innervated by the third, fourth, and fifth nerves, such as was 
found in case AS1.» (table 2). 
An examination of the shoulder musculature in cases AS2; and 
AS2,2. showed that here, too, all of the muscles which typically 
differentiate in the heterotopic position were developed (table 
3), and that all were supplied with peripheral nerves. The 
structures within the limbs showed essentially a normal arrange- 
ment and thenervesa normal intrinsic distribution. Theshoulder- 
girdles showed no defects other than a short suprascapula and 
a poorly developed procoracoid in case AS2), (table 4). 
Whether all of the heterotopic limbs of this series received the 
normal segmental nerve contribution cannot be definitely stated. 
