Migration of the frontal, parietal and temporal lobes has tended to bury an "island" of cortex within the depths of the lateral fissure (Figure 1-39 , Figure 1-40) . If parts of the frontal (red) and parietal (yellow) lobes are cut away this cortical area - the insula (violet) - is revealed, as shown here. Blumenfeld shows this in his Figure 2.24. The insula is not truly an island, however, and its relationship to the lobes of the hemisphere is best revealed by making a cut through the brain in the plane indicated by the line and looking at the surface of the sectioned tissue. We will see the section in the next view.