IRRITABLE PARTS OF FLOWERS. 25J 



Strained by the calyx, as those of the lovely Kahnia,{n6) 

 Curt. Mag. t. 175, 177, are by the minute pouches in 

 the corolla, relieve themselves by an elastic spring, which 

 in both instances serves to dash the pollen with great 

 force upon the stigma. The same end is accomplished 

 by the curved germen of Medicagofalcata^ Engl. Bot. t' 

 1016, releasing itself by a spring from the closed keel of 

 the flower. 



But of all flowers that of the Barberry-bush, t. 49, is 

 most worthy the attention of a curious physiologist. In 

 this the six stamens, spreading moderately, are sheltered 

 under the concave tips of the petals, till some extraneous 

 body, as the feet or trunk of an insect in search of honey, 

 touches the inner part of each filament near the bottom.,. 

 The irritability of that part is such, that the filament im- 

 mediately contracts there, and consequently strikes its 

 anther, full of pollen, against the stigma. Any other 

 part of the filament may be touched without this effect, 

 provided no concussion be given to the whole. After a 

 while the filament retires gradually, and may again be 

 stimulated ; and when each petal, with its annexed fila- 

 ment, is fallen to the ground, the h;tter on being touched 

 shows as much sensibility as ever. See Tracts on Nat. 

 History^ 165. I have never detected any sympathy be- 

 tween the filaments, nor is any thing ot Uie kind expres- 

 sed in the paper just mentioned, though Dr. Darwin, 

 from some unaccountable misapprehension, has quoted 



(116) [The ten stamens of the Kalmias are bent outward, and 

 their anthers confined hi the same number of depressions in the 

 corolla, until liberated in the manner described.] 



