DAILY iMOVEMENTS OF LEGUMINOUS LEAFLETS 



45 



position, a fall of 90°. This change — like the others — can be 

 seen with close observation. It is completed in about 20 minutes. 

 At the close of the movement the leaflets are down, lower side 

 to lower side. This position is maintained during the night. 

 It may be somewhat disturbed at the time of full moon. 



In Leucaena glauca, we have an example of a group of plants 

 in which the night position is above the horizontal instead of 

 below it. The leaflets fold forwards as well as upwards and 

 overlap. At break of day the leaflets begin to bend back. The 

 tip of the leaflet is the first part to show response. Graduallj^ 

 the whole leaflet bends out and back until it reaches the hori- 



Fig. 2. A. Gliricidia sepiam, showing the leaflets in the xerofotic position 

 in strong sunlight. Los Banos, P. I. June 24, 1913. B. Canavalialineala, show- 

 ing leaflets in the xerofotic position. Taal Volcano, P. I. March 7, 1915. 



zontal or day position. As in the other group, this position is 

 maintained until dusk, unless affected by strong, direct sunlight. 

 Tn this case the xerofotic response is brought about. In every 

 way the xerofotic position of this group is similar to the other, 

 as described in Gliricidia. The same factors govern resumption 

 of the horizontal position under suitable conditions during the 

 day and at dusk. At dusk, however, the movements are up- 

 wards and forwards into the night position. The night position 

 is maintained during the night, subject to the same irregularity 

 at the time of full moon, but in this respect Leucaena is less 

 affected than Gliricidia. 



The figures bring out the different positions. 



