CH. xiv TERMS USED IN DESCRIBING THE FLOWER 179 



be divided into equal halves in any plane, it is said to be regular 

 or actinomorphic. If the flowers of the Hyacinth and Wallflower 

 are examined they are seen to be regular or actinomorphic, for 

 if a sharp knife is used they can be cut into equal halves in any 



FIG. 181. Female flowers 

 Dog's Mercury. 



FIG. 182. Actinomorphic flower of the Primrose 

 the dotted lines show the planes of division. 



FIG. 183. Zygomorphic flower of the Pea ; the dotted lines show the plane of 

 division. 



plane which passes through the centre of the flowers. (Fig. 182). 

 The flowers of the Pea and Deadnettle can only be divided into 

 equal halves in one plane. Flowers of this kind are said to 

 be irregular or zygomorphic (Fig. 183). If a flower cannot be 



N 2 



