THE STRUCTURE OF THE FLOWER 329 



shape, giving an i/rregular flower, which is symmetrical about 

 one plane only — namely, that seen in the figure. There are ten 

 stamens, nine of which are united, while one remains free, and 



Fig. XXVII. — The Flower of a Pea (natural order Leguminosae). 

 thus the andrcecium is di-adelphous. The result of one stamen 

 being free is to leave a slit in the tube formed by the filaments, 

 through which the insect visitor can pass its proboscis when 



Fig. XXVIII. — The Flower of a Saxifrage (natural order Saxifragacese). 

 seeking for honey. The gynccceum, as we have abeady mentioned, 

 is monocarpellary (see also p. 252). 



