48 MEMBERS OF PLANTS. 



Centrifugal Evolution. 



In the centrifugal evolution, each branch or flower- 

 stalk terminates in a flower-bud, never in a leaf-bud, 

 and consequently it cannot be prolonged farther, as in 

 the centripetal, though it may shoot out fresh flower 

 buds from the sides, when nourishment is afforded. 

 Instead of a single floral leaf, each top flower has two 

 or more, and from the inner base of these two or more 

 new branches spring, each again ending in a central 

 flower, and two or more side branches. They proceed 

 forking off in this manner, till the supply of nourish- 

 ment is exhausted. All the flowers in the centre open 

 first. 



The form under this division may not inappropri- 

 ately be termed in general a bouquet 1 ; but when the 

 branches from the flower-stalk are wanting or very 

 short, it is termed a ball 2 , though differing only from 

 the tuft in its evolution. The bouquet, when the side 

 branches are very short, and the flowers crowded toge- 

 ther, is termed a fascicle 3 , as in sweet-william. The 

 bouquet is in some instances only simply forked, as in 

 silene and some of the pinks ; triply, or oftener forked, 

 as in spurge; or not forked at all, no flowers being 

 evolved on one side, as in bugloss and scorpion-flower. 

 Sometimes the bouquet resembles an umbel, and some- 

 times a bundle, but is always distinguished by its 

 peculiar evolution. 



(1; In Latin, Cyma. (2) In Latin, Glomus or Glumerulus, 



(3) In Latin, Fasciculus. 



