Amphicarpcea monoica. 313 



hour. Those recorded below were made during the Last 



week of June and early in July. I cannot speak exactly 

 for night movements earlier in the year, but the behavior 



at that season until 10 P.M. would indicate during the re- 

 maining hours decided similarity to that described for the 

 summer months. Between 11.30 P.M. and 2 a.m. the 

 terminal leaflet re-assumed gradually a nearly perpendicular 

 position, turning again, so that the margin instead of the 

 surface was more in the plane of the surface of the lat- 

 erals, but it still stood out from the remaining leaflets, the 

 apex inclining away from the petiole. The laterals had 

 rotated upon the pulvini, so that their upper surfaces in- 

 clined somewhat inward. 



Between 2 and 3 A.M. the terminal rose slightly, and the 

 laterals shifted so that their upper surfaces faced in the 

 normal direction. All leaflets were deflexed about 45 °, but 

 the spreading apart of leaflets was marked. 



From 3 a.m. the general attitude of a plant might be de- 

 scribed as that of expectation. About 4 a.m. the petioles 

 had arisen, and the day position was rapidly being as- 

 sumed. By 4. 30 some few leaflets had completely ex- 

 panded ; many at 4.45 a.m.; nearly all at 5 a.m. These 

 records are of green-house plants, temperature 2o°-25° C. ; 

 the hygrometer, 85°-90°. During this month the sun rose 

 at 4.35 a.m. 



Those out of doors varied greatly — clouds, winds, low 

 temperature retarded the assuming of the day position, al- 

 though during the night the leaflets showed similar 

 activity to that just described (unless it was very windy). 

 On a moderately warm morning, some were found in day 

 position at 5 a.m.; on a cool morning there was a delay 

 until 6 a.m., and even later. 



In this connection it may not be out of place to allude to 

 the Mimosas which were in the green-house. While Am- 

 phicarpaa was in agitation half the night, the leaflets of 

 Mimosa were quietly folded. When the time arrived for 

 the day position, the leaflets expanded in a very short time, 



