44 



BOTANY. 



floral circles the same number of parts ? Then it is a sym- 

 metrical flower. Any flower that has the same number of 

 parts in each of its circles is symmetrical ; and even if 

 some of the circles have just twice, or three or four times, 

 as many as others, it is still symmetrical. Count the parts 



FIG. 144. Binary Symmetry. 



FIG. 145. Ternary Symmetry. 



FIG. 146. Quaternary Symmetry. 



FIG. 147. Quinary Symmetry. 



in the floral circles of Fig. 145. Is this flower symmetri- 

 cal ? Does Fig. 146 represent a symmetrical flower? 147? 

 These kinds of symmetry are described as binary, tern- 

 ary, qtiaternary, and quinary. Examine the flowers you 

 have collected and discover, if you can, the symmetrical 

 ones, naming the symmetry they show. 



EXERCISE XVIII. 

 Complete and Incomplete Flowers. 



A complete flower consists of calyx, corolla, stamens, and 

 pistil. If any one or more of these flower-circles is absent, 

 the flower is incomplete. 



