The course of the blood stream through the labyrinth of the ear has been a subject of considerable uncertainty and difference of opinion among anatomists. The reasons are obvious, for the complicated series of cavities that go to make up the labyrinth of the ear makes the study of the blood supply by the ordinary method from sections very inaccurate, unless laborious methods of reconstruction are used. This element of difficulty was successfully overcome, however, when Eichler introduced the method of making celloidin casts of the labyrinth in which the circulation could be viewed in its entirety. But with this accomplished, and with such a complete picture of the blood supply before one, the complicated network of vessels found in the labyrinth of the adult ear is, in many places, very difficult if not quite impossible to disentangle with any degree of accuracy.
The arteries offer the chief difficulty, for