THE FLOWER 245 
D. Protective ADAPTATION 
EXPERIMENT 83. ARE THE FLORAL ENVELOPES OF ANY USE? — Care- 
fully remove the calyx and corolla from a young flower bud on a growing 
plant and see what will happen. Remove them from a flower just unfold- 
ing. Mark each by tying a colored thread lightly around the petiole and 
see if it sets as many seeds, or as good ones, as the unmutilated flowers on 
the same plant. 
EXPERIMENT 84. Is THE POSITION OF A FLOWER ON THE STEM OF ANY 
IMPORTANCE ? — Invert a blossom of pea or sage, and see what parts would 
come in contact with the body of a visiting insect. How would its chances 
for pollination be affected? Try to make a flower grow in an inverted 
position by tying or weighting it down, and watch the effect on seed pro- 
duction. 
EXPERIMENT 85. Is THE POSITION OF FLOWERS ON THE STEM INFLUENCED 
BY LIGHT? — Place a potted plant with expanding flower buds near a 
window so that the light will reach it from one side only, and notice the 
position of the buds. After a day or two reverse the position with regard 
to light, and watch whether any change of position takes place. 
EXPERIMENT 86. Is THE POSITION OF FLOWERS ON THE STEM INFLUENCED 
BY GEOTROPISM? — Lay a potted plant of lily of the valley, larkspur, 
358 359 
Fics. 357-359. — Flower of monkshood, showing the changes by which it returns 
to its original position under the influence of geotropism after the axis of inflorescence, 
x, has been inverted: 357, inverted position ; 358, change due to negative geotro- 
pism ; 359, change due to lateral geotropism. 
gladiolus, or digitalis in a horizontal position, tie the main stem to keep 
it from changing its direction of growth, and leave for two or three days 
in a place where it is lighted equally on all sides. How do the individual 
flowers behave? What part bends to turn them up? Vary the experi- 
