Question on salayatana

From Ñanavira's Notes on Dhamma: His note on Mano: > Note that just as the eye, as cakkhāyatana or cakkhudhātu, is that yena lokasmim lokasaññī hoti lokamānī ('[that] by which, in the world, one is a perceiver and conceiver of the world') (Salāyatana Samy. xii,3 ), i.e. that thing in the world dependent upon which there is perceiving and conceiving of the world, namely a spherical lump of flesh set in my face; so the mind, as manāyatana or manodhātu, also is that yena lokasmim lokasaññī hoti lokamānī, i.e. that thing in the world dependent upon which there is perceiving and conceiving of the world, namely various ill-defined parts of my body, but principally a mass of grey matter contained in my head (physiological and neurological descriptions are strictly out of place—see PHASSA).[c] This is in agreement with the fact that all five khandhā arise in connexion with each of the six āyatanāni—see NĀMA & PHASSA [a]. For 'perceiving and conceiving' see MAMA [a]. Why does he say "this is in agreement with the fact that all five khandhā arise in connexion with each of the six āyatanāni."?