Mtli lot us alba, L. and other Plants. 7$ 



Pi All X. 



Fig. i. Plant of Melilotus alba deprived of sufficient water. To be 

 compared with 



Fig. 2. which has been liberally watered. Both photographed at the 

 same time. 



Fig. 3. Plant photographed from the west At six o'clock, P.M., on a 

 bright evening after a shower. The leaves have all put themselves in posi- 

 tion to take the sun's rays at right angles and take all the light they can 

 get. Compare this with 



Fig. 4. Plant photographed at six o'clock, P.M., on a very dry, hot day 

 from the north. Leaves are all pointing directly at the sun. They are 

 parallel with the sun's rays, as in Plate IX, Fig. 4. 



Plate XI. 



Fig. 1. Plant in open air in sun. Observe the direction of the leaves, 

 and compare with 



Fig. 3. photographed at the same time, but under glass in a saturated 

 atmosphere. 



Fig. 2t. Plant under blue glass photographed at three o'clock, p.m. 

 Day dark. 



Fig. 4. Plant under red glass photographed at the same time as Fig. 3. 



Plate XII. 



Fig. 1. Plant in hot air and sun photographed at nine o'clock, a.m. 

 Leaves all pointing toward the sun. Photograph taken from south twenty 

 degrees west. 



Fig. 2. Plant placed under alum water to absorb heat rays. Tem- 

 perature about io° C. less than in the open air and sun. Leaves are more 

 horizontal 



Fig. 3. Plant under glass and packed in ice to keep the temperature 

 down. About 8° C. lower than in sun. Young leaves elevated. Older 

 ones less influenced. 



Fig. 4. Melilotus alba under red glass. Photograph taken at twelve 

 o'clock, midnight. Compare this with Fig. 1 Plate IX, plant under white 

 glass photographed at the same time. 



Plate XIII. 

 Fig. 1. Ordinary day position of leaves of Melilotus alba. 

 Fig. 2. Sleep, or night position. 

 Fig. 3. Hot sun position. 

 Fig. 4. Hot sun position at the same time on the other side of the 



plant. 



Figs, 5, 6 and 7. Different positions assumed to secure light. 

 Fig. 8. Sleep, or position of leaves under red glass. 



