Why is the primary visual cortex called area 17? · Grey Matter

In 1909 Korbinian Brodmann stained slices of cortex and found that the thickness and cell makeup of its layers change at sharp borders, and he divided the cortex into 52 numbered areas by that structure alone.

Why is the primary visual cortex called area 17?

In 1909 Korbinian Brodmann stained slices of cortex and found that the thickness and cell makeup of its layers change at sharp borders, and he divided the cortex into 52 numbered areas by that structure alone. The numbers follow the order in which he examined the areas, so neighbours can have distant numbers and the numbers carry no meaning in themselves. They stuck because the borders often coincide with functions: area 17 is the primary visual cortex, 4 the primary motor cortex, 3, 1 and 2 the somatosensory cortex, 41 and 42 the primary auditory cortex, 44 and 45 Broca's area.