The boundaries of the subregions are not well defined.
The eastern and western halves ale contrasted in climate-the former being moist and the latter dryand have been distinguished by some zoologists as distinct subregions.
This region naturally comprises the African and Indian areas, conformably to be called subregions.
The linear subregions are then constructed in this new space instead of the high dimensional shape space.
Hence, cells typically consist of many different subregions exhibiting different (physical) properties.