Phototropism was originally called heliotropism, or bending toward the sun, until scientists found out that plants would bend toward light in general, not just sunlight.
12.
Yet other species ( notably sunflower ) are capable of reorienting their leaves throughout the day to optimize exposure to the Sun : this is known as heliotropism.
13.
The " M�moires . . . " published some important new ideas : Malus on the dimorphism ) ( 1809 ); Gay-Lussac and Thenard on the discovery of the amides of metal ( 1809 ); Candolle on heliotropism ( 1817 ).
14.
Among these are his investigation of the periodicity of growth in length, in connection with which he devised the self-registering auxanometer, by which he established the retarding influence of the highly refrangible rays of the spectrum on the rate of growth; his researches on heliotropism and geotropism, in which he introduced the clinostat; his work on the structure and the arrangement of cells in growing-points; the elaborate experimental evidence upon which he based his " imbibition-theory " of the transpiration-current; his exhaustive study of the assimilatory activity of the green leaf; and other papers of interest.
