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Re:Mixing Compact fluorescents and other bulbs

       From: "S. Hieber" <shieber at yahoo_com>
       Date: Sun, 1 Jul 2001 07:20:57 -0700 (PDT)

>"How do the plants know
>the lights are so much brighter in another part of the tank?  "

>I am not a botanist but my botany teacher told me that, the plants
>knowing nothing, grow more cells or larger cells in inverse proportion
>to the light striking those parent cells.  The result is that the
>shadier side grows faster and therefore, plants bend towards the light
>(or the brighter light).  Possibly a similar photochemical action makes
>flowers follow the sunlight over the course of the day.  Any really
>botanists out there?

The bending towards the light is caused by a hormone, auxin, that is
released at the growing tip and moves down the stem.  Auxin causes cell
elongation.  When a stem is lit from one side, somehow, the auxin
concentrates at the opposite side, causing these cells to elongate more
than the cells on the lit side, causing the stem to bend towards the light.

Paul Krombholz, in  central Mississippi where we have received above normal
rainfall for the month of June.