THE PHILIPPINE 
Journal of Science 
C. Botany 
Vol. VIII NOVEMBER, 1913 No. 5 
DAILY GROWTH MOVEMENTS OF LAGERSTROEMIA 
By Edwin Bingham Copeland 
{From the College of Agriculture, University of the Philippines, 
Los Banos, P. /,) 
Curvatures due to growth, made and eliminated regularly in 
each twenty-four hour period, are well known as phenomena of 
the growth of the young leaves, or young flowering branches or 
shoots, of many plants. They have been most carefully and ex- 
tensively studied by Darwin,^ who called them "nyctitropic.** 
Pfeffer, who also made a careful study of these movements, 
designated them as "nyctinastic," because, while they are caused 
by the succession of day and night, the direction of curvature 
is independent of the illumination. The only statement known 
to me as to the occurrence of nyctinastic curvatures in leafy 
branches is one in Pfeffer's Pflanzenphysiologie, ed. 2, 2: 484, 
to the effect that they have been observed by Vochting in the 
branches of Mimulus Tilingii, 
What Vochting reports ^ is not a movement of the ordinary 
vegetative branches, but of flowering branches which incidentally 
bear leaves; "Dieselben Vorgange, die wir an der Hauptachse 
beobachten, finden sich wieder an den Seitengliedern, wenn diese 
Bliitenstande bilden, und zwar sowohl an den kleineren, als 
an den grosseren." He made no real study of the cause of the 
movement, but says: "Doch glaube ich auf Grund einiger 
Beobachtungen annehmen zu diirfen, dass die fragliche Streck- 
ung theilweise auf dem Einflusse der Schwerkraft, theilweise 
und vielleicht hauptsachlich auf dem der Rectipetalitat beruht." 
The temperature also is believed to be one of the controlling 
factors. 
^ Power of Movement in Plants, Chapters VI and VII. 
'Berichte Deutsch. Bot. Ges. 16 (1898) 37. 
120864 287 
