Datensatz

Zusammenfassung

The orderly projection of the visual space onto the visual ganglia and of the planes of the four visual ganglia onto each other is briefly reviewed. The variation of the size of some of the elements in the eye and of the ganglia is then described. This variation follows different gradients for different elements. The gradient of the size of the lenses in the cornea and that of the thickness of the L3 fiber in the lamina have a similar shape, with a maximum near the anterior border of the eye. The thickness of L1 and L2 follow a different rule. A correlation of these gradients with some variations of the efficiency of visual stimuli in different regions of the visual field leads to a tentative proposal for the role of the laminar neurons L1, L2 and L3 in perception.

This paper is organized in tow section. In the first, I shall collect information about the structures of the eye and the visual ganglia of the fly, insofar as they fit into the periodic scheme which makes the mapping of the various levels onto each other possible. In the second part, on the background of this periodic structure we shall discuss some striking quantitative variations which follow warious gradients throughout the visual system. This second part is largely drawm from a paper written together with H. HAUSER, which is now in press.