Abstract
The sensory epithelia of the vertical canals were saddle-shaped riding upon the septum transversum of the ampulla with the long axis right-angled to the canal. The sensory epithelium of the horizontal canal is just of the half cut in the middle of the vertical one in shape, and a little larger than that in size. In the middle part of the sensory epithelium, the sensory cells were larger in the surface of each cell, while in the lateral periphery which distended fan-wise the sensory cells were smaller in the cell surface. The average numbers and areas of sensory cells in three samples were 3427, 0.2506mm2 in the lateral crista, 4293, 0.2835mm2 in the anterior one, and 4403, 0.2939mm2 in the posterior one. The horizontal crista was smaller in size and less in number than the vertical one in the frog.
