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26 later, i.e., at 6-50 The temperature, after reaching

the maximum, began to fall at 12-25, and the previous movement of fall of the stem was arrested and reversed into an erectile movement shortly after 1 There are thus two "turning points," one at 7 , and the other at about 1 ; at these periods the movement of the plant remains more or less arrested for more than half-an-hour.

I obtained records of similar diurnal movements with various procumbent or creeping stems. Figure 7 gives the diurnal record of the procumbent stem of a young specimen of Mimosa pudica.

The experiment that has just been described shows clearly that geotropic curvatures of stems is opposed, or neutralised to a greater or less extent, during rise of temperature, and this antagonistic reaction is removed during the fall of temperature. The diurnal movement of the