BEES AS FERTILISERS. 



307 



to pieces, it will be seen that the keel petals have 

 each a protuberance, which fits into a corresponding 

 hollow on the inner sides of the alae, so that the 

 latter cannot be depressed without carrying the keel 

 with them. This is really what happens when the 

 bee settles. The style, forming part of the rigidly 

 set pistil, relatively rises between the keel petals, 

 and touches the bee on the thorax, as at B, leaving 



Fig. 65.— Papilionaceous Blossoms, and their Method of Fertilisation. 

 A, Expanded Pea Blossom, Order Leguminosce—v, Vexillum ; al, Ahe with Carina 

 between. B. Partial Section of Flower of Vetch being Fertilised by Cyprian 

 Bee (Magnified Twice), Right Ala removed below line a, b-v , Vexillum; 

 ri, Nectai^Gland ; aV Ala ; c, Carina containing the Pistil, .the Stigma of which 

 is striking the Bee's Breast. C, Section of Pistil, showing Ovules (Peas) 111 

 Ovary—?*, Nectary ; a, a', Anthers ; s, Stigma. 



some pollen, which may be placed on the stigma of 

 the next flower. All this can be easily seen, by hold- 

 ing the blossom steadily, and pushing down the alae 

 with the fingers. At the departure of the insect, the 

 style again retires, to repeat the process if necessary. 

 The stigma first touches the bee's body, so that crossing 

 is brought about; and then, as the tongue is employed 

 in sweeping up the nectar, a new supply of pollen 

 is given ; so that, in visiting a succession of blossoms, 

 the pollen of one is transferred to the stigma of the 

 next The description now given applies to Lathyrus 



2 B 2 



