298 Schively — Contributions to the Life History of 



each circle was completed at the expiration of 1 hour and 

 10 minutes. The next period began at 1.45 p.m., and was 

 completed in 1 hour and 20 minutes. The date was 

 February 5 ; weather was clear and sunny. The tempera- 

 ture was 26 during the greater part of the time; it began 

 to decrease during the last one recorded. The last circle 

 required 2 hours and 1 minute, and during this time water- 

 ing of greenhouse took place; the temperature having 

 fallen to 21 ° C. Observations ceased at 5.21 p.m. 



A plant was observed June 20; the height was 16 inches 

 and it was not supported. From 6.21 a.m. to 8. 10 a.m. 

 a circle was completed in 1 hour and 49 minutes; tempera- 

 ture 23 C. At 9. 13 a.m. observations began again; in 1 

 hour and 27 minutes another circle was made, then fol- 

 lowed another in 1 hour and 7 minutes. The slight 

 increase of time required for the circle made from 11.49 

 a.m. to 12.59 P.M., is probably due to a fall of n° in the 

 hygrometric conditions ; since at this part of the day, a 

 more rapid movement should have resulted. The tempera- 

 ture averaged 29 C. The circle was 12 inches in diame- 

 ter ; observations could not be continued, as the plant after 

 this, became caught in the frame. The main stem of this 

 plant had been truncated, and the actively circumnutating 

 shoot was one which had developed in the axil of a com- 

 pound leaf. 



One plant on a hot July day, interested me greatly. It 

 was about 14 inches high; before daylight it required 2 

 hours and 15 minutes for a revolution, the temperature 

 being 21 C. At 12.47 pm., I observed it once more; 

 from that hour until 4.49 p.m., four large circles were 

 made; the first in 55 minutes, the remainder in 60 minutes 

 each. The temperature was very regular, 31 ° to 32 C, 

 but it fell a little, just before the close of the last period. 



In some cases, I have been able to study one plant 

 through several successive days, at least for a portion of 

 the time. Thus the varying phases of individuality, 

 growth, time of day and temperature, are more emphati- 



