抄録
1) It is demonstrated that the peripheral cut end of the medullary bull-frog's trigeminal nerve is stimulated by means of Kotsuka's “glycerine spot method” intracranially, there follows a pupillary constriction on the isolateral eye.
Therefore, it is evidenced that there exist efferent pupilloconstricting fibers in the trigeminal nerve.
2) Pupillary dilation is observed on the atropinized eye when the peripheral cut end of the trigeminal nerve is stimulated intracranially with “glycerine spot method” as in 1).
Thus, it is demonstrated that there exist efferent pupillodilating fibers in the trigeminal nerve besides the above evidenced efferent pupilloconstricting fibers.
3) It is revealed that efferent trigeminal pupilloconstricting fibers dominate over efferent trigeminal pupillodilating fibers of a non-atropinized eye.
4) The results of 1) and 2) support to consider that the iris musculature of bull-frogs is governed by “efferent trigeminal double innervation”.
5) The above experimental results are presented to disapprove Langley's law of double innervation of the centrifugal autonomic nerves on the iris.
