154 MANUAL OF NATURB 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 

 flov/ers 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 



