A450 S. W. RANSON AND P. R. BILLINGSLEY 
Serial sections of the trunk including the first lumbar ganglia 
and the origin of the second splanchnic nerve, stained with osmic 
acid, were examined. In the trunk below the thirteenth thoracic 
ganglion and the origin of the greater splanchnic nerve the major- 
ity of the fine myelinated fibers had degenerated. There were 
present, however, normal myelinated fibers of all sizes rather 
widely separated from each other by degenerated material. 
These were the afferent fibers of the tenth, eleventh, and twelfth 
white rami. The lesser splanchnic had the same structure as the 
thirteenth thoracic internodal segment. 
Cat XIV. Killed thirty-two days after section of the roots 
of the tenth distal, and those of the eleventh thoracic nerve 
proximal, to the spinal ganglia (fig. 7). In osmic acid prepara- 
tions of the trunk including the tenth, eleventh, and twelfth 
thoracic ganglia, the tenth white ramus could be seen entering 
the trunk. It contained six or eight normal fine myelinated 
fibers, but except for these was completely degenerated. It 
could be traced down the trunk as a sharply defined fascicle 
occupying a superficial position. In addition to the half-dozen 
fine myelinated fibers that could be traced in along with the 
tenth ramus this degenerated area became invaded by a few fine 
myelinated fibers that worked their way into it from the normal 
part of the trunk. 
The white ramus of the eleventh nerve could also be traced 
into the trunk. It contained a small number of large fibers and 
a somewhat greater number of medium-sized and small fibers. 
These normal fibers were separated by a considerable amount of 
unstained material representing the degenerated preganglionic 
fibers. These normal and degenerated fibers of the eleventh 
white ramus could be followed down the trunk where they could 
be seen to occupy a position adjacent and partially superficial 
to the fibers from the tenth ramus. 
The bundles from the two degenerated rami presented a marked 
contrast. That of the tenth contained only a few fine myelin- 
ated fibers, that of the eleventh a much greater number of all 
sizes. The latter are easily accounted for as afferent fibers with 
their cells of origin in the eleventh thoracic spinal ganglion. 
