FLORAL SYMMETRY. 



125 



stant number ; in Fig. 384, four is the prevailing number ; 

 while in Fig. 385 it is five. 



What numbers have occurred oftenest in your written 

 descriptions of flowers ? When you describe a flower, 

 observe always what figures you use in numbering its 

 parts, and decide what number the plan of the flower is 

 based upon. 



EXERCISE LVIII. 



Alternation of Parts in Flowers. 



Figs. 387 and 388 represent the stamens and pistil of 

 the flower shown in Fig. 386. Does this picture represent 

 a perfect flower ? Does it repre- 

 sent a complete flower? a regu- 

 lar flower ? a symmetrical flower ? 

 Fig. 389 is a cross-section of this 

 flower, given to illustrate the re- 

 lation of the parts to each other. 

 Observe that the petals alternate 

 with the sepals; that is, they stand 

 opposite to the openings between 

 the sepals. In the same way the 

 stamens alternate with the petals, 



FIG. 386. 



FIG. 387. 



FIG. 388. 



and the carpels with the stamens. This regular alterna- 

 tion of parts is spoken of as a symmetrical arrangement 



