Beautiful Flowering Shrubs 



comes like a little worm just as one squeezes a " worm " 

 of cream out of a chemist's collapsible tube. With a 

 hand-glass one can watch the whole process beautifully, 

 if a pencil or finger play the part of the bee. Again, just 

 as one can squeeze the collapsible tube time after time, get- 

 ting out fresh cream with each pressure, so bee after bee 

 alights on and can press the keel again and again, causing 

 successive fresh exudations which smear each visitor's 

 abdomen and legs. But ultimately the keel becoming 

 less and less resistant every time there comes an occasion 

 when it is pressed down so far that the horn of the 

 seed-case is thrust after the pollen through the keel point, 

 and as it rubs on the insect's body it becomes smeared 

 with the pollen which is resting there, and which was 

 probably brought from other flowers. Finally the petals 

 fall, and a quaint twisted pod quickly develops from 

 every fertilised blossom. 



In the Bladder Senna, Colutea arborescens, the flowers 

 are set five or six together in clusters ; the petals are 

 more compact, the big standard is often bent right back 

 on itself ; the wings clasp the keel as in Coronilla. Here, 

 when the insect straddles them, there is no vermiform 

 emergence, but a mass of loose pollen is pressed out 

 through the keel by the top of the hook-like projection 

 from the pod. This pollen can be seen resting on the top 

 of the hook, but it is not fertilising the ovules in the 



pod, for the receptive part is the under side of the hook, 



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