Responses of single retinal ganglion cells in different areas of mouse retina were studied to determine their cone inputs, using spectral sensitivity functions and chromatic adaptation. Spectral sensitivity curves were based on threshold response criteria to full field stimulation. The retina of the mouse was viewed through a dilated pupil with a surgical microscope. Ganglion cells were classified into three groups: one receiving inputs from short wave sensitive cones, a second receiving inputs from only middle wavelength sensitive cones and a third receiving inputs from both of these types of cones. The ventral retina, contained a large fraction of the first group of ganglion cells. The dorsal retina and the border between these two areas contained relatively more of the latter two groups. A small fraction of cells were found which displayed antagonistic-like interactions between photoreceptor systems. The results demonstrate that single ganglion cells in mouse retina can select responses from only one of the two cone mechanisms present in this retina, even in areas containing both types of cones.