INTRODUCTION 3 
E. The Flower. “Note that the stem bears flowers at intervals. 
Decide from what definite points they may arise. Make a reduced 
drawing of a short piece of stem with a leaf and a flower-stalk, bearing 
a flower. Draw (natural size) a side view of a flower with a bit of 
flower-stalk attached. Note that a spur extends backward from the 
flower nearly parallel to its stalk. Look at the outside and the 
inside of the flower to see how the rather leaf-like, bright-colored 
parts of which its principal bulk is made up are arranged with refer- 
ence to each other. The five outer leaves, taken together, are called 
the calyx, and the five inner ones the corolla. Cut off the calyx 
leaves nearly at their bases, pull off the spur and all the corolla 
leaves, and draw the remaining organs more than natural size. Note 
that there are eight curved stalks, each of which bears a knob at its 
tip. These are called stamens. Decide whether all of the stamens 
mature at the same time. Within these is a much shorter object, 
divided at the-tip into three portions. This is the pistil. See whether 
the stamens and the pistil maturé at the same time. 
F. The Fruit. Note that after the flowers wither all the parts 
except the pistil gradually fall off, and that the lower portion of the 
pistil finally develops into a green, three-lobed fruit. Cut across the 
largest and ripest fruit that can be obtained and ascertain how many 
seeds each lobe of the fruit contains. 
The production of seed is the office of the flower, and 
the use of seeds is to reproduce the plant, since each per- 
fect seed can under favorable circumstances grow into an 
individual like the parent plant. The formation of the 
seed is due to the action of pollen, a substance produced by 
the stamens. In some plants the pollen appears like fine 
dust, but in the majority of showy flowers, as in the nas- 
turtium, it is a sticky, yellow, brownish, or reddish powder. 
The pollen acts in a very complicated way (Chapter xv1) 
on the rudimentary seeds borne within the base of the 
pistil, and causes them to develop into perfect seeds. 
