662 A. F. Goldjarb 
similar sections of limbs of a corresponding stage of development, 
taken from paralyzed or partially paralyzed animals. 
Another animal (No. 2.8) preserved 55 days after the amputation 
had regenerated a new limb 3 mm. long, bearing 4 toes. All the 
elements of the leg, foot and four toes were laid down. ‘The nerves 
have degenerated farther proximally than in the preceding, and 
the rate, extent and kind of degeneration are quite the same as 
described under paralyzed and partially paralyzed individuals. 
In the pelvic region there was no trace of degeneration either of 
the cellular or the fibrous layers of thecord or of the nerves between 
the base of the hind legs and the lumbo-sacral plexus. 
No. 15.4 is worth mentioning because the limbs bore no external 
sign of regeneration, although 59 days had elapsed since amputa- 
tion. Internally the proliferation of cartilage and the formation of 
“embryonic’”’ tissue had proceeded less rapidly than 10.4. The 
nerves were practically the same as 2.8. 
In No. 2.8,, the leg had grown 4 mm. long, with four distinct 
toes, during the 116 days after amputation. The nerves had 
degenerated still farther proximally, in fact close to the base of the 
leg. But of special importance are the extensive constructive 
changes whereby the regenerated nerve fibers have replaced in 
large part those broken down. ‘This is about at the same rate as 
the regenerative changes in partially paralyzed animals, in No. 5.2 
for example. ‘The destructive changes did not affect the cord or 
nerves proximal to the base of the legs. 
No. 2.10 is interesting, for though the regenerating period was 
the same as 2.8,, the nerves had degenerated from the amputated 
end only as far as the knee, not above it. Like the preceding the 
nerve fibers have grown back again towards the regenerated leg. 
In 1.48 the limb has been cut off above the knee, and 184 days 
thereafter the animal was preserved. The new motor nerve 
fibers have largely replaced the degenerate ones and reached almost 
to the cut level, while the sensory fibers have penetrated to a con- 
siderable distance within the new limb. 
The few instances above, but too briefly touched upon, and 
chosen from a large number, are perhaps sufficient to make clear 
an outline of the history of the nerves after ordinary amputation 
for purposes of comparison with other cases. 
