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ventral root passes upwards and splits into two bundles, 
one penetrating the dorsal, the other the ventral ganglion. 
Both roots emerge from the atlas vertebra by a single 
foramen (fig. 17). 
The following nerves arise from the dorsal ganglion: 
1. R. communicans (7. com. 2).—A sensory nerve 
arising from the extreme dorsal tip of the dorsal ganglion. 
Passes upwards and forwards, bends forwards over the 
roof of the skull, and fuses with the R. spinosus ec. of the 
first spinal nerve (gq. v.). 
2. R. spinosus (7. sp. 2).—A motor nerve passing 
upwards internal to the dorsal ganghon. After giving off 
a fine motor twig below, which passes upwards external 
to the dorsal ganglion (and not shown in the chart), it 
liberates in front and above a larger motor nerve which at 
once splits into two bundles coursing laterally in the 
dorsal musculature—one anteriorly and the other pos- 
teriorly (see chart). - Above, it receives the sensory R. 
communicans from the third spinal nerve in the typical 
manner, and bends forwards over the roof of the skull, 
keeping very close to the middle line. 
The following nerves arise from the ventral ganglion: 
1. R. medius (7. m. 2).—A mostly motor nerve, 
which perforates the ganglion, and then turns laterally 
backwards in the dorsal musculature. It breaks into two 
—one coursing in the dorsal musculature above the R. 
lateralis profundus vagi, and the other crossing below it 
into the lateral musculature, and supplying the muscles 
in these regions. It seems to contain some sensory fibres 
also. 
2. R. ventralis (7. v. 2)—A mixed nerve perforating 
the ganglion and coursing downwards and backwards over 
the kidney and approximating to the R. ventralis of the 
first spinal nerve. It receives two Rami communicantes 
