This research will quantitatively describe the development of the inner plexiform layer synaptic arrays of goldfish, mouse, xenopus and chick. Description will include growth curves of both synaptic densities and of the mean number of synapses per amacrine cell or bipolar cell. Retinal loci to be surveyed are both central and peripheral. In addition, the effect of experimental paradigms on the arrays will be investigated. The effects of thyroxine and luteinizing hormone on synaptic array development will be studied.