Influence of the Nervous System 651 
cord in the lumbo-sacral plexus had been completely destroyed, 
as determined from a study of serial sections. 
No.1.27. Tailwasamputated 5mm. fromitsbase. Nervecord 
was removed by broach for20mm._ After this both hind legs were 
amputated below the knee. Animal preserved fifty-two days 
after the operation. ‘The hind limbs had regenerated one and one- 
Fig. 2 Cross-section of the spinal column of D. viridescens through the first plexus nerve and ganglia. 
Shows complete removal of the nerve cord. Inner end of roots shown on the left. A, neural arch; 
C, connective tissue replacing nerve cord; G, sensory ganglion, end section on the left, median section 
on the right; C/, proliferated cartilage; M, inner end of motor root; S, inner end of sensory root; N, 
space formerly occupied by nerve cord. 
half and 1 mm., respectively, and three toes were distinctly formed 
on each leg. No movement of the limbs occurred even after 
strong stimulation. 
Sections showed the total absence of the nerve cord, its membranes 
and the proximal part of the roots from the region in which all three 
plexus nerves take their origin. ‘The neural canal is partly tilled 
with delicate connective-tissue cells. Fig. 21s a cross-section not 
