102 BRITISH FLOWERING PLANTS chap. 



species, passing over, however, the more general points, 

 such as the secretion of honey, the colour of the corolla, 

 the radiating lines on the petals, and the smell. 



1. Why is the flower situated on a long stalk, which 

 is upright, but curved downwards at the free end ? — 

 In order that it may hang down ; which, firstly, prevents 

 rain from obtaining access to the honey ; and, secondly, 

 places the stamens in such a position that the pollen 

 falls into the open space between the pistil and the free 

 ends of the stamens. If the flowers were upright the 

 pollen would fall into the space between the base of the 

 stamen and the base of the pistil, and would not come 

 in contact with the bee. 



2. Why does the pollen differ from that of most 

 other insect-fertilised flowers ? — In most of such flowers 

 the insects themselves remove the pollen from the 

 anthers ; and it is therefore important that the pollen 

 should not easily be detached and carried away by the 

 wind. In the present case, on the contrary, it is desir- 

 able that it should be looser and drier, so that it may 

 easily fall into the space between the stamens and the 

 pistil. If it remained attached to the anther it would 

 not be touched by the bee, and the flower would remain 

 unfertilised. 



3. Why is the base of the style so thin ? — In order 

 that the bee may be more easily able to bend the style. 



4. Why is the base of the style bent ? — For the 

 same reason. The result of the curvature is that the 

 pistil is much more easily bent than would be the case 

 if the style were straight. 



5. Finally, why does the membranous termination 

 of the upper filament overlap the corresponding portions 

 of the two middle stamens ? — Because this enables the 

 bee to move the pistil, and thereby to set free the pollen 

 more easily than would be the case under the reverse 

 arrangement. 



V. tricolor (Pansy). — This is a very variable 

 species. The stipules are large, leaf-like, and divided 

 into several more or less narrow lobes. Bentham and 



