652 A. Ff. Goldfarb 
quite at right angles to the axis of the animal, and through the 
origin of the first plexus nerves. This particular section was 
chosen because it shows among other things the proximal end of 
the roots, and it is seen that they do not extend within the vertebral 
canal. These roots lead into the spinal ganglion, only a part of 
which is seen at this level. On the opposite side, the section 
passes through a more median plane of the ganglion. It will be 
observed that the ventral or motor root is far more degenerate than 
its dorsal mate, and that both roots neither connect with the cord 
nor with the roots on the opposite side. ‘They end abruptly at 
the neural arch. 
The conditions within the neural tube, seen in Fig. 2, persist 
unchanged throughout the plexus region as well as throughout 
the tail. There is no trace of a nerve cord or nerve cells. 
For the sake of ensuring better fixation, the limbs were frequently 
preserved separately. In this case it was found on examination 
that between the spinal column and close to the amputated end of 
the limb, the nerve fibers were perfectly normal. Near the latter 
end, however, the myelin had broken down into globules, charac- 
teristic of degenerating nerves. No trace of nerve fibers were 
found in the newly regenerated part of the leg. 
Unfortunately, the region anterior to the first plexus ganglion 
was not preserved, sothat no definite statement concerning it can be | 
made. Nevertheless it is quite certain that every source of motor 
stimulation emanating from the plexus proper, to the very end of 
the tail, was completely removed and that no regeneration of the 
cord into this region occurred. “Vhe hind limbs were completely 
and permanently paralyzed, and unable to respond to very strong 
stimuli. Examination showed that the regenerated structures con- 
tained no motor nerves. ‘The nerves like those in the frog degener- 
ate very slowly, for after fifty-two days only that part of the nerves 
nearest the amputated end had degenerated. The remainder of 
the fibers appeared quite normal. 
According to Waller, Marinesco, Halliburton, Harrison and 
other investigators nerve fibers may be regenerated and con- 
sequently stimuli may be transmitted only when the nerve cells 
are present. In this case, however, these have been destroyed. 
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