REPRODUCTION BY SEED 181 



The head (Pig. 80) is the characteristic inflorescence of 

 the Dandehon family, the scabious, thrift, etc. The 

 flowers are small, very closely packed, and borrounded 

 by a ring of small leaves (bracts). 



Pro. 79. — DiAOBAM OF Cnss, 



The umbel (Pig. 81) occurs in the Parsley family (the 

 UmbeDiferse), the onion, narcissus, pelargonium, etc. The 

 flowers are again usually closely packed, and in some of 

 the Umbelliferse — e.g., hogweed — the outermost petals of 



FlO. 80. — DiAQBAH OF HSAD (CaFITULTTII). 



each flower are enlarged to increase the size and con- 

 spicuousness of the whole cluster. 



In considering the biological significance of the various 

 forms of inflorescences, we see that in all cases the flowers 

 arc so arranged as to increase the chances of pollination. 



