The development of pigment cells in the eyes of rhesus monkeys

The eyes of rhesus monkeys possess two lines of pigmented cells: those of the pigmented retinal epithelium and those of the uveal tract, also known as stromal pigmented cells. The cells of the pigmented epithelium differentiate first and are fully functional in 65‐day old fetuses. By contrast, stromal pigmented cells do not become recognizable until late gestation (140 days). The differences in development and structure of these cells may reflect a different and perhaps distinct function.