TUFTED VETCH 153 



and below the stigma clothed with long upwardly-directed hairs, which 

 are longer and closer on the outer than on the inner side, and form 

 a brush. The anthers lie close to the brush and pollen falls from them 

 on the latter at an early stage, when the stigma is at a lower level than 

 the hairs, included in the pouch formed by the flat top of the keel, 

 when the latter is depressed projecting from the narrow slit at its 

 extremity. The alae serve as levers for insects to depress the keel, 

 and they are united in two places with the edge of the keel. In the 



TUFTED VETCH (Vicia Cracca, L.) 



middle of the upper border there is a deep fold in each ala fitting into 

 a corresponding hollow in the keel, which lies in front of the pollen 

 cavity. The wing bulges in and forms a depression behind this fold 

 which fits into a second cavity in the keel, and the two fit very closely, 

 the cells interlocking, in a similar manner to the above structures. 



The return of the wings and keel to their former position after an 

 insect visit is ensured by their elasticity, by aid of processes on the 

 alae that clasp the staminal column, and others on the carina that 

 serve the same purpose, and by the broad base of the standard, which 

 curves laterally to clasp the claws of the alse and the carina, the calyx 

 holding the standard in position. The flower is visited again and 



