Cones in the retina of the Mongolian gerbil,Meriones ...
· The peak of sensitivity at 420430 nm, and the small number of blue cones in the Mongolian gerbil may explain why Jacobs and Neitz (1989) could not detect blue cones in their SSC measure ments which were extended down to 440 nm only. The presence of at least two spectral classes of recep tors active at high illuminance levels may be inferred from the .