A NOTE ON THE RELATIVE RATES OF DEGENERATION IN THE CROSSED AND THE UNCROSSED RETINOFUGAL FIBERS IN THE OPOSSUM DIDELPHIS-MARSUPIALIS

The rates at which the crossed and the uncrossed components of the ret inofugal pathway degenerate in Didelphis has been studied by light and electron microscopical methods. We have found that in Didelphis, as i n Monodelphis the two components can be clearly distinguished at the l evel of the chiasm. However, in contrast to the situation previously d escribed for Monodelphis, where the uncrossed component degenerates mo re rapidly than the crossed, both components degenerate at the same ra te.