94 THE FIRST BOOK OF BOTANY. 



FIG. 172. FIG. 17?. FIG. 174. 



NOTE. The difference between definite and indefinite flow- 

 er-clusters is shown above. Fig. 172 represents an indefinite 

 raceme, the growing end of which is surrounded by unopened 

 flowers. In Fig. 174 the reverse is the case; the rachis ends 

 with a flower the oldest flower of the .cluster, while at the 

 other end, near the peduncle, the buds have scarcely .begun to 

 unfold. This, therefore, is clearly a definite raceme. In Fig. 

 173 the oldest flowers of the cluster are near the peduncle, 

 the growing end is surrounded by undeveloped buds, and its 

 kind is easily determined. 



