CH. VI, 5] METHODS OF CROSS-POLLINATION 



297 



(Kalmia), partly irritably, as in Barberry, and diversely in 

 some Orchids, though the exact significance of these~lthd 

 other like phenomena is still matter of debate. 



FIG. 209. Clusters of Larkspur, showing the diageotropism of the flowers. 

 The tip of the larger cluster was tied down at an early stage of its devel- 

 opment. (Drawn from a photograph.) 



There remains one leading question ^Why these elaborate 

 arrangements for cross-pollination when close -pollination is 



