140 
PLANT STUDIES 
if necessary, the parts of the leaf or the stem itself twisting 
to allow the blade to assume this position. The danger of 
the leaves shading one another is reduced to a minimum by 
the elongation of internodes, the spiral arrangement, short- 
ening and changing direction upwards, or lobing. 
This outlines the general nutritive relations, the roots 
FIG. 143a. Germination of the garden bean, showing the arch of the seedling stem 
above ground, its pull on the seed to extricate the cotyledons and plumule, and 
the final straightening of the stem and expansion of the young leaves. After 
ATKINSON. 
and leaves being favorably placed for absorption, and the 
latter also favorably placed for photosynthesis. 
98. Placing of flowers. The purposes of the flower seem 
to be served best by exposed positions, and consequently 
flowers mostly appear at the extremities of stems and 
branches, a position evidently favorable to pollination and 
seed dispersal. The flowers thus exposed are very com- 
monly massed, or, if not, the single flower is apt to be large 
and conspicuous. The various devices for protecting nec- 
tar and pollen against too great moisture, and the more 
