"All our farinaceous plants contain abundance of , especially wheat, barley, oats, maize, rice, ; and the s differ from each other in size and form so decidedly, that they cannot well be mistaken by a careful observer. They are prepared for the microscope, and sold as polariscope objects, because the examination of a starch granule with shows it with a beautiful black cross, revolving with the polarizer; or, if over a selenite stage, a brilliant play of colours is obtained."