2 go 
T. W. Woodhead and M. M. Brierley. 
through an angle of 45°. At 8.30 p.m. on the same day the branch 
was raised 2°, and at 10.20 a.m. on June 26th it was raised 20°, in 
which position it remained. The branch had in fact lost its tendency 
to twine and continued afterwards its normal course. In another 
case a branch curved at its base in such a way as to carry the shoot 
through an angle of 30°, from 7.45 p.m. to 10.20 a.m. the following 
morning. During the day, which was fairly bright, the upper part 
of the shoot erected itself and grew on in a normal direction, 
leaving only a slight curve at the base which became fixed. In a 
third case a branch shewing a faint trace of bending was marked 
on June 15th. By June 22nd it had made half a turn and by 
July 4th the coil was completed. The shoot made a complete 
dextrorse turn around the petiole of its subtending leaf. Meanwhile, 
a number of branches which had not been marked, completed their 
coils in a shorter period. It seemed curious that we were so 
unsuccessful in selecting favourable branches: still this is not 
surprising when we remember that a considerable number of 
branches, after curving to a slight extent, assumed a more or less 
normal position and continued their growth without further 
variation. It was also noticed that on dull days the coiling was 
more steady and continuous than on bright days. 
It frequently happened that the curve produced during a dull 
period was more or less neutralised during a bright period. The 
twining branches noted up to this stage, i.e., the end of June and 
early in July, had developed during a comparatively calm period. 
There was an absence of high winds, and the Shirley Poppies (sown 
behind them in the same border) had not as yet made their 
appearance. What was thought might be another contributory 
cause of twining was overcrowding, but up to this time the plants 
were too far apart to admit of this explanation. It was not until 
much later that the lateral branches had grown sufficiently to come 
into contact with each other, so that high winds, friction due to 
rubbing against their own or the rougher Poppy stems, or over¬ 
crowding, could not be seriously considered as contributory causes 
in this season’s plants. As might be expected, when the plants 
were more fully developed and more numerous branches formed, a 
much larger number of twining shoots was observed. That this 
was during the period of overcrowding may fairly be put down as a 
coincidence and not a cause. 
As seen above, from May 13th to June 13th twenty-five out of 
the forty plants had developed twining branches, by June 30th 
