70 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



IT 18 19 20 21 22 23 24 25 26 27 28 

 March, 1900 A 



10 



mm-' 



5mm- 



17 18 19 20 21 22 23 24 25 26 27 28 



March., 1900 



B 



Fig. 24. -i4, grand period of growth of etiolated scape of Arisaetna triphyllum 

 plotted from daily maximum rate. B, grand period of growth plotted from total daily 

 amount of growth. 



lOlT 



6PM. 



6A.M 



6PM. 



6 A.M. 



6PM. 



6 A.M. 



6 AM. 6PM. 6A.M 6PM 6 A.M. 6PM. 



Fig. 25. Curve showing rate and amount of growth of prophvll of Arisaetna 

 triphyllum in dark chamber. The measurements were begun when the prophj^ll had 

 reached a length of 3 cm. and ended five days later when it had ceased to elongate at a 

 length of 35 cm. The distance from the base line to the curve denotes the actual amount 

 of growth during the two-hour periods, the maximum being about 4 mm. per hour. 

 The temperature of the dark room was 22° C. at the beginning of the observations and 

 gradually fell to 20° C. near the end. 



