Figure 4. Eye diameter and activity pattern in newborn strepsirrhine primates.

Left column, log10 transformed axial eye diameter, transverse eye diameter, and orbital aperture diameter plotted against cranial length in primates with different activity patterns. Note that all cathemeral and diurnal scale below the regression line for nocturnal primates. Right column: relative size (residuals) of the same measurements. Although no significant differences were found, nocturnal species show a trend toward relatively larger eye dimensions than cathemeral and diurnal species. The difference in orbital aperture dimensions is less apparent.