Chapter LXXXI: Section 124: Proceeding from the brain are twelve pairs of cranial

nerves. From the fore-brain spring two pairs, which differ from the rest of the cranial nerves in being, first of all, hollow outgrowths of the brain-- the others are from the beginning solid. The first nerve is the olfactory lobe, which sends numerous filaments through the ethmoid bone to the olfactory organ. The second is the optic nerve, the visual sensory nerve.