124 Experiments on the Development of Peripheral Nerves 
cells from the ganglion crest would be able in the absence of the motor 
ganglion cells to form the purely motor rami of the spinal nerves. There 
are difficulties in the way of making this experiment because it is first 
necessary to cut off the dorsal half of the cord, leaving it attached at one 
end, then by a second cut to remove the ventral half entirely, and 
op. Cf \ 
is 
Mot.Nuc’ ." 
Dy’ 
Fig. 3. Semidiagrammatic view of the nerves of the abdominal walls of the 
frog larva (normal specimen). Abd. M., abdominal muscle; HL., rudiment of 
hind leg; Mot. N., motor branch of segmental nerve running in inscriptio 
tendinea of the primary abdominal muscle; Mot. Nuwc., motor nucleus (ventral 
horn cells) in spinal cord; Seg. N., segmental (spinal) nerve; Sen. N., sensory 
branch of spinal nerve running to integument outside of muscle; Sp. C., spinal 
cord; Sp. G., spinal ganglion. 
finally to heal the first strip, which is very thin, back in place. Even if 
this is done successfully, a scar is left, which lies in the path of the 
