-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- so for many centuries the people of xuchotl dwelt in their city , cultivating the fertile plain , until their wise men learned how to grow fruit within the cityfruit which is not planted in soil , but obtains its nourishment out of the airand then they let the irrigation ditches run dry , and dwelt more and more in luxurious sloth , until decay seized them .