PRATT's paper is an argument of the hypothesis—1st. That the cones alone are the terminal cells of the optic fibers in the human retina. 2d. That the rods are supporting tissue to the cones, their outer segments practically forming a part of the pigment epithelial layer. 3d. That the tenth, or pigment layer, is that in which light vibrations are changed into nerve stimuli.
Reference:Arch Ophthalmol. 1898;27:222.
A look at the past . . .. Arch Ophthalmol. 1999;117(9):1266. doi:10.1001/archopht.117.9.1266