Figure 1 of Biswas, Mol Vis 2010; 16:2328-2341.

Figure 1. SEM overview of fiber cell membrane surfaces of fractured intact embryonic chicken lens (E18) along the anterior/posterior (median sagittal) axis. This fractured axis is for examination of ball-and-sockets on the short sides of cortical fiber cells. An approximate zone for the abundant distribution of ball-and-sockets is outlined. In the equatorial region, the ball-and-socket zone extends at least 300 μm deep from the surface. In the images, B&S zone, ball-and-socket zone; AP, annular pad; N, nucleus; AS, anterior surface; PS, posterior surface.