Influence of the Nervous System 649 
There often appeared to be considerable differences between the 
regenerated legs of operated and of control animals. “These how- 
ever were found to be largely due to the indirect consequences 
following the operation. For example, the paralyzed limb 
amputated at or below the knee assumes such a position, that 
the weight of the body largely rests upon the cut surface, thus forc- 
ing the regenerating end to grow at a sharp angle to the axis of 
the stump. ‘The new foot and leg become permanently twisted, 
which gives the whole limb a very abnormal appearance. The 
abnormality was further augmented by the degenerating muscu- 
lature of the stump. Not infrequently the number of toes were 
reduced from five to four or even three, but this reduction is not 
uncommon among newts that are injured in other ways, and not 
rare among control animals. 
A variation of the above experiment consisted in first amputating 
the limbs and at varying intervals thereafter in destroying the lumbo- 
sacral plexus. This experiment was intended to test whether 
the removal of nerve impulses had a retarding or inhibiting or 
other deleterious influence upon a limb that had already begun to 
regenerate. Nosuch influence was observed. ‘The rate and ex- 
tent of growth, the shape and the size of the newly formed limb 
were virtually the same as in the control series. Once begun 
regeneration was not affected by the destruction of the motor 
nerve cells supplying the limb. 
In the first series of experiments it is possible that the brief 
initial stimulus between amputation and paralysis may have 
sufficed to start the cycle of changes that end in the formation of 
anew limb or part thereof. That an incredibly short stimulus 
may suffice to start and maintain the regenerative processes to the 
completion of an organ was shown by the writer in Eudendrium 
ramosum.?. To avoid the briefest initiatory stimulus, the limbs 
in a third series were amputated after paralysis. ‘The intervals 
varied from a few days to several months,which in the latter cases 
at least was sufficiently long for all the motor nerves of the para- 
lyzed limbs to have degenerated. Nevertheless newlegs developed. 
2 Goldfarb, A. J.: Light as a Factor in the Regeneration of Eudendrium ramosum, Journ. Exp. 
Zobl., 1905. 
