60 WAYSIDE WEEDS. 



instead of corolla, are not perfect flowers, botani- 

 cally speaking. Be it remarked, too, that not 

 only must these parts be present, but they must 

 be developed in a regular series of circles, or whorls, 

 -as they are called, the organs alternating one with 

 the Other; the corolla divisions alternating with 

 those of the calyx, the stamens with the divisions 

 of the corolla on the one side, and with the parts 

 of the pistil on the other (Fig. 42)i These relative 

 positions are, of course, altered by variations in 

 nimiber and development, but stiU. titiey afford to 

 botanists a standard by which to judge in the 

 determination of doubtful parts. . 



