Circumnutation of Some Flowering Plants. 67 
in producing the accelerated movements, as compared with 
those obtained by Darwin. 
Convolvulus Sepium.—Young actively growing shoots of 
this species were observed in the greenhouses of the Botanic 
Garden for four days and nights by members of the class in 
continuous relays. Note was made of the temperature of the 
house, and of the prevailing atmospheric conditions outside. 
A dark sky and low temperature (15 C.—19.5 C.) gave dis- 
couraging figures for the first three days. The quickest time 
made during the period was 1 hour 45 minutes; the longest, 
4 hours I5 minutes; average, 2 hours 40 minutes. The 
twenty-fifth of the month was a clear day and the temperature 
ranged from 15.5 C. to 33.5 C., resulting oncein a circumnu- 
tation in 57 minutes: the longest took 3 hours; the average 
time for the day was 1 hour 5314 minutes. The behavior of 
the plants with respect to light and temperature would point 
to Darwin’s conclusion, that both are important factors in plant 
movement. 
The rainy days afforded no good opportunity for observa- 
tion of periodicity of growth, but the clear day caused an 
acceleration of movement from 8.05 a. m. till 2.30 p. m. in 
one ease, and from g a. m. till 4.32 p. m. in another, the suc- 
cessive circles being : 
SPECIMEN I 
Pash empler2 43 2e5 odie ch at ake site 2 hours 30 minutes. 
SECOND CELE Coote fear dae tare Ihour 45 “6 
yc Wee edt Cepeeseall Sy Fe ae es oe ese ae a 
SPECIMEN 2. 
Lpes FS iosl gee a a aes et oe ae 2 hours. 
SeeRMER EMEROL > Cet fools Te ered Me a 3 1 hour 50 minutes. 
Whird eirelesti is ft. Girdiz?. 2) <2) ans OS 35 “e 
F curele CIRCLES Fides 5 ood ca ag ja Sa et 5: /1%< 3:30 =< 
VEN CIEL ey Se Se se, cee os ae oe = 2 a 
pextienreler coe ele, eet cep a ls 57 a 
The night circumnutations were longer than the average 
daily ones. 
