Then the wind catches in the leaves and flowers and bends the stems an 
limitations of the prevalent method of gas analysis, and has str! 
34 BOTANICAL GAZETTE. | February 
branches, so that the flowers are most conspicuous on the same side. . 
have seen the heads of Helianthus grosse-serratus turned to the northeast 
by a southwest wind, and the bees were flying southwest, and thus ap- 
proached the heads in front. But the flower-stalks often whip about, 
easily shaken by the wind, and when turned to any position remain in it. 
Prof. W. W. Bailey says:? “The flowers are made to assume their defi- — 
nite position by friction of the pedicels against the subtending bracts. 
Remove the bracts and they at once fall limp. This was shown me b 
Prof, Goodale in 1879.” With the breath one can easily blow the flowers” 
to the opposite side of the spike. 
Prof. Coulter * has observed how the movement of the flowers is use 
ful in bad weather by turning their mouths from a driving rain, but 
think it is also advantageous in fair weather in adaptation to the flight 
insects. ; 
Iu September, 1886, I found several hundred stalks of Physostegia 
_Virginiana arranged in a long patch along the railroad. The south west 
wind was blowing up the road, and the flowers were all turned away from | 
the wind, so that they looked to the northeast. As I walked through 
the patch from the southwest, I passed nineteen humbie-bees, Bombus 
Pennsylvanicus*‘ (females and workers), all going against the wind, except 
two, which did not visit the flowers regularly but flew away to the north: 
éast. Returning, I overtouk the bees going against the wind, but Pp assed 
none going with it. Keeping their faces to the wind, they would move 
from side to side, or even let themselves back to a spike they were 4 
to leave behind. It was interesting to observe that, while the wind 
quired the bees to face it, it compensated for the disadvantage by cart 
ing the odors to them and by turning the flowers so that they were m0 
easily seen and visited by them.—CHaRLES ROBERTSON, Carlinville, dil. 
Conditions of Assimilation.’—In this paper Dr. Pringsheim notes ' 
by direct observation of the protoplasm to determine the seat and 
tions of the various functions. It seemed likely that the observation 
protoplasmic movements in varying conditions of light and darkpess : 
in partial or total removal of oxygen, would afford a suitable 5 
2 Bor. Gaz. vii, 122. 
