The development of the primate retinal vasculature was investigated in fetal monkeys (Macaca mulatta) during the latter half of gestation. Vascularization is retarded in the region of the macula. The macula becomes completely encircled by a network of primitive capillaries which then proliferate centripetally towards the presumptive fovea. These encircling vessels normally cease to proliferate before reaching the center of the fovea, and the resulting central avascular zone and centripetal pattern of vessels persist thereafter in the mature macula. The superficial peripapillary network of capillaries, like the outer vascular net, is derived from the inner network of vessels.