In probability, the motor nerve fibres coming from the tractus pyramidalis cruris cerebri are represented by the nerve fibres running along the rhaphe to the chief and median nuclei after or without decussating, while the sensory nerve fibres are represented by the fibre group coming from the stratum griseum centrale partially decussating and fibres running longitudinally through the chief nucleus, but many points are not yet in the clear on the subject.
The ending formation of the external motor and sensory nerve fibres in the oculomotor nucleus could not be elucidated satisfactorily, but I certainly could not observe any simple terminal networks around the cells and others as would have been expected according to the Langley's neuron theory. On the contrary, these fibres, after branching and anastomosis in the neuroglia tissue, seem to go over into extremely complex intranuclear plexus found around the nerve cells and their processes. Though many points remain to be clarified regarding the formation of this plexus, it is at least certain that the strongly stainable thick fibres represent motor and sensory nerve elements and the minute fibres showing fine reticular formation, vegetative nerve elements.
The majority of the oculomotor nerve root is composed of decussating fibres at the lower part of the oculomotor nucleus, originating mainly from the dorsal side of the chief nucleus and partly from the ventral side thereof. These head first toward the inner ventral part of the same side, then abruptly drop to a point a little above the lower end of the fasciculus longitudinalis medialis, cross over the median line, return upwards to penetrate the chief nucleus of the opposite side and enter the fasciculus longitudinalis medialis. In the upper part of the nucleus the decussating fibres are found extremely small in number. They emerge from various sides of the chief nucleus and attain the opposite side without running such a devious course. Also some of the median fibres coming from the upper part of the median nucleus apparently decussate in their course.