Fig. 4. Formation of the L'-PLL line. (A,B) The pattern of PLL neuromasts just before and after the L' line has formed. The neuromasts of the L line are not numbered; the dotted arrow (in grey) outlines the distorted geometry of this line due to unequal migration. (C) Each neuromast of the D, D', L, and L' lines later forms a vertical ‘stitch’. The frame corresponds to the boxed area in B, at an older stage. Anterior is towards the left and dorsal is upwards.