Two Remarks on the Visual System of the Frog

Abstract

Abstract This chapter discusses retinal anatomy and proposes that a deciphering of this anatomy is possible. The relative size of dendritic field to receptive field is such that the anatomical and functional groups can be matched. In attempting to decipher the anatomical differences by means of the functional differences, the discussion comes to the hypothesis that, with respect to the discrimination of silhouettes, the inner levels of the inner plexiform layer are concerned with boundaries, whereas the outer levels are concerned with average, or changes in the average, illumination. This hypothesis can be extended to account for the fact that bipolar cells that end exclusively in the outer levels of the inner plexiform layer are connected only to cones, whereas those that end deepest in the inner layers are connected to both sorts of rods as well as the cones.