[274]

July 31st to Aug 4' 1878

Pinus pinaster

circumnutated of young leaf

Plant 5 inches high in Pot. — needle 1 inch long — glass filament affixed almost transversely across tip Stem tied close beneath leaf — distance at first 12 inches from vertical glass (under skylight). (At 7° a.m on Aug 2d. Pot pushed a little further off viz to 14 1/4 inches from glass so as to magnify more.) [sketch] 

(The leaves rise on apex tip of shoot almost upright but some diverge: one a a young one a little divergent was selected for observation & it was alm very nearly 1 inch in length: those a little lower were 1.15 inch in length; the lower ones become more & more divergent & soon extend horizontally from stem.) From 11° 45' a.m on 31' of July to 6. 40' a.m on Aug 1. the movement was divergent, slightly zig-zag (Tracing I) which caused the the mark to sink. On Augt. 1. circumnutated above same point. The divergence recommenced in evening evening & during during night. — On morning of Aug. 2d to morning of Aug 4th there was plain though slow circumnutated with no divergence, though ultimately if leaf had been watched for a week or two the sum of the movement wd. certainly would have been divergence, effected by modified circumnutation.

Changes of light during the different days will did not explain changes in nature of movement.