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nerve-root. dnr Dorsal nerve-root. a Nerve-tube subdi- 
viding outside the spinal cord. pe Periphery of the spi- 
nal cord. CC Central canal. Int Longitudinal nerve-tubes. 
Int Longitudinal nerve-tubes giving off side-branches. snt 
Subdividing nerve-tube. snf Subdividing nerve-tube cros- 
sing the central canal. 
Fig. 112. (Magnified 1 60 diameters.) Part of a chroiiio-silver stained 
horisontal section of the spinal cord. The letters have 
the same signification as in fig. iii. hr Slender branches 
given off from the nerve-tubes of the dorsal nerve-root. 
» 113. Dlagrame of the reflex-curve The large arrows indicate 
the way the irritation of a sensitive nerve-tube has to 
pass to produce a reflex-movement. SN Centripetal (sen- 
sitive) nerve-tube. dd Dotted substance or interlacing of 
nervous fibrillæ in the central nerve-system. MN Centri- 
fugal (motoric) nerve-tube. 
The small arrows indicate the way small parts of the 
irritation of the centripetal (sensitive) nerve-tube pass to 
arrive in other parts of the central nerve-system. i Nerve- 
tube passing to the brain. 2 Longitudinal nerve-tube 
running along the spinal cord, whilst giving off side-branches. 
sne The nutritive centre of the centripetal nerve-tube 
(i. e. spinal ganglion cell). ene The nutritive centre of a 
part of the fibrillæ forming the dotted substance or inter- 
lacing of nervous fibrillæ (i. e. ganglion cell of the central 
nerve-system). mnc The nutritive centre of the centrifugal 
nerve-tube (i. e. ganglion cell of the central nerve-system j. 
2Jpr Nutritive (i. e. protoplasmic) processes sometimes 
issuing from the nutritive centres, and penetrating towards 
the periphery of the central nerve-system or towards 
blood-vessels to absorb nutrition. a 8ib Periphery of the 
central nerve-system. 
