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 cahjx, 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 cui-ved 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. AVithiu these is a much shorter object, 

 divided at the-tip into three portions. This is the jnslil. See whether 

 the stamens and the pistil mature at the same time. 



F. The Fruit. Note that after the flowers wither all the parts 

 except the pistil gTadually fall off, and that the lower portion of the 

 pistil finally develops into a green, three-lobeil /;•«//. 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 xvi) 

 on the rudimentary seeds borne within the base of the 

 pistil, and causes them to develop into perfect seeds. 



