We have studied transneuronal retrograde cell degeneration in the monkey retina after striate cortex removal. We find that the amount of ganglion cell degeneration depends on the age of the monkey at the time of lesion when the survival period is held constant. Monkeys lesioned between 2 and 15 months of age showed up to 80% ganglion cell loss after a 1 year survival period, whereas adults surviving for 1 year showed only a 15% loss.