660 A. Ff. Goldfarb 
its proper size, is egg-shaped in section, with its long axis horizontal. 
The lumen is a mere slit. The fibrous layer has largely degener- 
ated. In places the middle of the slit comes together to form 
two separate lumina, thus forming a double cord. A little farther 
caudad a clump of cells have formed a smaller dorsal nerve cord, 
which enlarges posteriorly. The ventral one only connects with 
the plexus nerves. The two finally fuse, the two lumina unite to 
form one, and slightly beyond both the cords disappear from the 
rest of the plexus region. | 
No. 1.25. The left limb moved slightly two days after the oper- 
ation, and from this time on there was a steady increased ability 
to move the limb. By the 71st day it moved quite normally. The 
right leg however remained paralyzed. 
Like 1.1 B, the cord of this animal was injured on one side only, 
and like 1.20 it clearly showed that a considerable degree of regula- 
tion in the nerve cord may take place. Plexus nerves II and III 
are cordless. Plexus nerve I takes its origin in a cord, the cells, 
fibers and roots of which have been destroyed onone side, namely, 
the right. The cord however has rounded itself out around an 
extraordinarily large lumen, eccentrically placed, and innervates 
the left leg, enabling it to move. 
No. 5.2. The legs remained paralyzed for 117 days. During 
the next 10 days they moved slightly. The cord had been injured 
over an area beginning 6 mm. anterior to the plexus and extending 
almost as far as the origin of the second plexus nerve. Posterior 
to this region the spinal column was cordless. In the first men- 
tioned area the cord is extremely degenerate, as indicated by the 
small diameter, vacuolized fibrous layer, and irregular shape and 
large size of the lumen. It ends in an irregular mass of minute 
degenerate cells. From these appearances we may infer that the 
cord had not been totally destroyed, but that a number of cord cells 
continuous or nearly so had been left. “These have made abortive 
attempts to develop into a new cord. Under tail regeneration 
evidence will be brought forward for believing that while the cord 
can round itself and even grow laterally, i.e., grow nerve fibers, 
posterior regeneration at this level never takes place. The im- 
provised cord can make enough motor connections with the limbs 
