MICHIGAN EXPERIMENT STATION BULLETINS 



3G3 



''^ 



Fig. 42. a- Leaves of a plant 

 nearly related to alfalfa or 

 lucerne as tbey appear in 

 daylight. 



b. The same 

 as seen by 

 night. 



Fig. 41. a. Leaf of a kind of 

 tobacco as seen in dapy- 

 time. 



b. Tiie same leaf asleep 

 at night. 



Fig 44. a. Leaf of a 

 kind of pepperwort, 

 Marsilia quadri- 

 folia, as seen during 

 the day. 



b. As seen when be- 

 ginning to go to 

 sleep. 



Fig. 43. a. Leaves of a foreign tropical 

 plant, Desmodhim gyratis, as seen 

 during the day. 



b. The same leaves as seen during 

 night. 



