148 On Flowers and Insects, 



into a triangular space at the end of the keel. Into 

 this space the pollen is shed (fig. 5 !,/<?). It must 

 also be observed that each of the wings has a pro- 

 jection (c) which locks into a corresponding depres- 

 sion of the keel, so that if the wings are depressed 

 they carry the keel with them. Now when an 

 insect alights on the flower, its weight depresses 

 the wings, and as they again carry with them the 

 keel, the latter slips over the column of stamens, 

 thus forcing some of the pollen out at the end of 

 the keel and against the breast of the insect. As 

 soon as the insect leaves the flower, this resumes its 

 natural position, and the pollen is again snugly 

 protected. The arrangement in the Sweet Pea is 

 very similar, and if the wings are seized by the 

 fingers, and pressed down, this outpumping of the 

 pollen may be easily effected, and the mechanism 

 will then be more clearly understood. 



2. It will be observed (fig. 50) that one stamen is 

 separated from the rest. The advantage of this is 

 that it leaves a space through which the proboscis 

 of the bee can reach the honey, which is situated 

 inside the tube formed by the united stamens. In 

 those Leguminosae which have no honey, the sta- 

 mens are all united together. Such flowers are, 

 nevertheless, in spite of the absence of honey, visited 

 by insects for the sake of the pollen alone. 



In other Leguminosae as, for instance, in the 

 Furze and the Broom the flower is in a state of 

 tension, but the different parts are. as it were, 



