Influence of the Nervous System 687 
tioned by a non-nervous tissue, the notochord. Previously 
Kolliker had pointed out—though not known to the writer at the 
time of experimentation—that the distal region of the tadpole tail 
was supplied by nerves that take their origin in the anterior por- 
tion of the tail. Under such circumstances the removal of the 
nerve cord need not and probably did not remove nerve stimuli 
from the amputated surface. Morgan and Davis are not explicit 
with regard to the levels at which their operations were made, nor 
how much of the cord was removed in each animal. 
29 mm 
SY ODO 
if 5 Wm 
Fig. 8 Distribution of the nerves in the tail of the tadpole of a frog. Semi-diagrammatic. The 
nerves arise in the anterior half of the tail. The dorsal ganglia also limited to basal half of the tail. 
Length of tail, 29 mm. Sensory ganglia extend over anterior 15 mm. only. L, leg. 
The following experiments were undertaken to re-examine these 
questions. A number of normal tadpoles were preserved in Her- 
mann’s fluid, and cut in serial cross-sections. The distribution 
of nerves in the tail was found to differ radically from the nerve 
distribution of Diemyctylus. In the latter each vertebra of the 
tail from the base to the tip, encloses a pair of dorsal ganglia and 
