92 ONOBRYCHIS, GENISTA. [CHAP, 



more so than the inner ones. The inner ones, on the 

 contrary, produce much more pollen than the others ; 

 a difference of function which is even more marked 

 in the Lupins. 



Ononis is exclusively fertilised by bees, and H. 

 Miiller has repeatedly seen male bees visiting this 

 species in a vain search for honey. 



Onobrychis sativa (the Common Sainfoin) agrees with 

 Trifolium repens (Clover) in its general structure ; but 

 the wings are greatly reduced in size and appear to 

 serve only in preventing the honey being reached from 

 the side, or at least in rendering this more difficult. 

 This species is sufficiently conspicuous, and as the 

 honey is accessible even to insects with a short pro- 

 boscis, it is much visited. When mature, the stigma 

 projects I to ij m. beyond the keel, and according 

 to H. Miiller the flower has lost the power of self- 

 fertilisation. 



In Genista tinctoria the ten anthers lie in two dis- 

 tinct rows. While the flower is still in the bud, the 

 four upper anthers of the outer row are already on the 

 point of opening, while those of the inner circle have 

 not nearly reached their full size. These four anthers 

 now open and shed their pollen into the space at the 

 apex of the keel, after which they shrivel up. The 

 fifth, although it has attained its full size, remains 

 closed. The next process is that this anther and 

 those of the second row also open, and the pollen 

 occupies the end of the keel between the anthers and 

 the stigma, as in Lotus. While, however, in Lotus 

 when the insect leaves the flower and the pres- 

 sure is thus removed, the keel resumes its position, 



