Influence of the Nervous System 657 
animals. The le{tleg—second amputation—had been amputated after 
the total degeneration of the motor nerves, yet 1t too had regenerated 
5mm. long with 5 normal toes. The nerves in this leg differed from 
those on the right side only in the less extensive disintegration near 
the amputated end, due to the difference in time since the amputa- 
tion of the two sides. ‘There is no sign of medullated motor fibers 
in either of the regenerated limbs. 
No. 1.43. December 16, 1907. Nerve cord destroyed in and 
beyond the lumbar region. 
January 11, 1908. Right leg amputated below knee. 
July 14, 1908. Right leg preseved 185 days after amputation, 
211 days after paralysis. . 
March 14, 1908. Left leg amputated. 
May 3, 1908. Left leg below knee preserved. 
July 14, 1908. Left leg preserved 139 days after amputation, 
211 days after paralysis. 
The spinal cord was totally absent from the plexus and from 
three of the vertebrz anterior to the plexus, i. e., for about 5 mm. 
This animal is particularly worth mentioning because we have 
indubitable evidence that the sensory nerve fibers have begunto grow 
back againinto the limbs. ‘he nerves give the impression of early 
stages of degeneration already described. Beginning at the spinal 
ganglia, the plexus nerves contain normal medullated fibers. ‘The 
nerve bundles to be sure are very thin, due to the absence of motor 
fibers. “This pseudo-normal condition, which extends but for a 
short distance towards the base of the legs, is gradually replaced 
by an atypic region containing many of the degenerate characters 
already described. Further examination made it clear that this 
atypical region is a region of active regenerative changes. In the 
first place the spaces between the fibers increase; secondly, the 
fibers diminish considerably in diameter; thirdly, these narrow 
into mere strands of protoplasm with an elongate denser central 
body; fourthly, the strands disappear leaving lines of spindles 
which in turn lead distally to the globules of the typical Wallerian 
degeneration. 
No. 1.42. Left leg amputated 110 days after paralysis. 
Preserved 145 days later or 255 days after paralysis. Regener- 
