208 



HOUSE, GARDEN, AND FIELD 



coloured, being yellow at the base and black beyond. The 

 colours of London Pride flowers are no doubt particularly 

 attractive to this fly. To an Ascia the red spots on the 

 petals and the crimson ovary glistening in the sun would 

 look as attractive as sweetmeats to children. Quite at 

 the bottom of the ovary each petal shows a pair of large 

 yellow discs which to a microscopic eye would resemble 

 honey-drops. The appearance is delusive, but before 

 the fly discovers his mistake, his head is close to the real 

 nectary? and here he finds his reward. 



Small, open flowers, growing many 

 together, white or pale-coloured, spotted, 

 and either scentless or giving out. a scent 

 which is disagreeable to man, are the 

 usual marks of a fly-pollinated species. 

 The umbel-bearers furnish many familiar 

 examples. The flowers of Horse-chest- 

 nut, however, which are pollinated by 

 bees, resemble in everything but size a 

 fly-pollinated species, the colours being 

 iust the same as in London Pride. We 



FIG. 46. -Petal of J 



London Pride; the have had occasion to remark that one 

 upper dots are red, the sax ifrage of our gardens, the purple or 



lower ones yellow. r r 



opposite-leaved saxifrage (see p. 87), is 

 pollinated by butterflies, a circumstance which has strongly 

 affected the form and colour of its flowers. 



When the flowers of London Pride wither, none of their 

 parts are shed, except the petals and stamens, and even 

 these often persist in a dry and shrivelled state. The 

 twin capsules of the fruit burst open at the top as soon 

 as the numerous seeds are ripe. The dry flower-stalks are 

 springy, and well adapted for throwing out the seeds in a 

 high wind. When ripe fruits of London Pride were kept 

 for a few days in a watch-glass set upon a large sheet of 

 paper, it was found that the seeds simply dropped out, 

 and were not shot off. Dry capsules with numerous small 

 seeds are commonly emptied by rocking in the wind. 



