This 30 years-old paper is not very well known, but I find it fascinating. In the retina, axons of ganglion cells converge to the optic disk where they then form the optic nerve. The optic nerve is myelinated, but the part of the axons within the retina is not. Because all axons first meet at the optic disk, there is a conduction delay that depends on how far the cell is from the optic disk. The surprising result in this paper is that the conduction time in the optic nerve (from the retina to the LGN) is inversely correlated to the conduction time in the retina, so that the total conduction time is invariant (arguably, there are not so many data points, just 12 cells). This suggests the existence of developmental plasticity mechanisms that adjust axon size (or distance between Ranvier nodes) for synchrony.