midnight. 
if the day is very hot.” 
Circumnutation of Some Flowering Plants. 
there is a gradual decrease in the rate, until several hours after 
The maximum period may be much extended, 
beginning earlier and continuing until 4 or perhaps 4.30 p. m., 
From the tables compiled by the 
writer, the following comparison of four-hour periods is 
obtained. The agreement of these statistics drawn from five 
species of plant, with the statement above quoted need merely 
be noted. 
Between the hours were performed 
Se aS nS ee ee ee II circumnutations. 
LSD THEE Ce ees: i eee 12 Ke 
Wen So ot) 2a? eeebabeek On ames It “s 
fe | ee ere Samo Joe ae 16 < 
Up i, eee owe ae ee 19 <6 
Fe ES OP toes Peake aaa eee 23 a 
BaP EY eee tr ton tk Se A Grote “ 
AT DARWIN’s Home. 
Phasentus. \(Geenhoase, May 2) 21.02.06 ss -) th 
Wiumeules. «, (“*Hot-weather”) ... ..... 2h. 
CORDOIIMIUS Not MMe ine AEE) SS aa eke: ee mae th 
Memera. x, (Haase, Apuk gz). os. 5) ed Sd 7h 
Westevia.. (May EG) i sa eh cee spe tah ls oe 202 2h. 
AT UNIVERSITY OF PENNSYLVANIA. 
Phaseolus. (Greenhouse, April5) ........ Ih 
ae os tk: SS es eee Ce eh: 
fHumulus. - February 9). = =:.5 < : rh. 
Convolvulus. “i March: 25np ae oo 2". i 
Lonicera. Lh ont ee Ye. 1) ke De 
“ ADS: ESS = welch eid | o> i th 
Wisteria. ea ak ae et oe 2h: 
When the experiments were begun, it was thought that 
under our comparatively bright sky and warmer temperatures, 
as contrasted with the atmospheric surroundings of England, 
circumnutations might be performed more rapidly than in the 
shortest time-limits given by Darwin. 
son of the two sets of results: 
Subjoined is a compari- 
. 55 m. 
8 m. 
. 42m. 
. 30 m. 
5 m. 
. 20 m. 
5 m. 
57 m. 
48 m. 
. 43 m. 
