232 FREAKS OF PLANT LIFE. 



facts themselves are placed on record, and hereafter 

 the key to the mystery may perhaps be found. 



Spontaneous movements are common in the organs 

 of reproduction, being more or less associated with 

 the process of fertilization. " In Stylidium, an Aus- 

 tralian genus, the style and filaments are adherent 

 into a column, which hangs over on side of the flower. 

 When touched it rises up and springs over to the 

 opposite side, at the same time opening its anthers 

 and scattering the pollen. The stamens of the various 

 species of berberry {Berberis and Mahonid) exhibit 

 this irritability to a remarkable degree. If touched 

 with a pin or other object at the base of the inside 

 face of the filament, the stamen will spring violently 

 forward from its place within the petal, so as to bring 

 the anther into contact with the stigma, and will, 

 after a time, slowly resume its original position. At 

 first sight it may seem as if this contrivance were 

 intended to ensure the fertilization of the pistil from 

 the pollen of its own flower. In reality, however, the 

 reverse is the case ; the excitation takes place in 

 nature when an insect entering the flower for the 

 sake of the • honey in the glands at the base of the 

 pistil touches the inside of one of the stamens. The 

 pollen is thus thrown on to the head or body of the 

 insect, which carries it away to the next flower it 

 visits, and leaves some of it on the stigma, and thus 

 cross-fertilization instead of self-fertilization is secured. 



