154 
MANUAIy OF NATURE) STUDY. 
The Fascicle is a cyme with flowers much crowded, 
as sweet williams. 
A Glomerule corresponds to the head. The 
flowers in a glomerule expand from the center out¬ 
ward, i. e. centrifugal, while the flowers of a head ex¬ 
pand from the outside toward the center, or cen- 
tripetally. 
Does the sunflower expand centripetally or cent- 
rifugally? How about the clover? The iron 
weed ? The lily of the valley ? What steps would 
you imagine a sunflower to take in order to become 
a spike ? Which form of flower cluster is most 
conducive to self-fertilization? For wind-fertiliz¬ 
ation? For insect-fertilization ? Why ? 
Give an opportunity for extended discussion 
upon the values of each form relative to fertiliz¬ 
ation. Let the discussion be based upon field 
observation of insects at work as well as upon 
adaptation of form. 
4. Become familiar with several of our common 
families of flowering plants. All plants that bear 
flowers are called flowering plants. We have 
families of people, families of animals, and strange 
to say, families of plants. We group together all 
plants that resemble one another in flower, seed 
and fruit, and say that they belong to a certain 
family. For instance, we say that the bean, the 
red bud or judas tree, the honey locust and the 
