THE PLANT AND ITS HELPERS 



953 



whereas in a normal case the 

 stamens were responsible for five 

 thousand. Even this number is 

 small compared with the quantity 

 of pollen grains produced by the 

 Dandelion, estimated at nearly four 

 hundred thousand ; whilst in the 

 case of the Paeony the number has 

 been placed at between three and 

 four million ! 



There is no doubt that insects 

 are often attracted to flowers by 

 their appearance and scent. ]\Iany 

 blossoms advertise their presence 

 by the gay colours which they 

 display and the sweet perfumes 

 which they exhale. Almost all 

 kinds of flies are very prone to 

 settle on anything which is strik- 

 ingly marked, and not a few 

 plants have turned this tendency 

 to account. The observations of 

 many students of this particular 

 phase of plant life have gone to 

 show how gaily coloured flowers 

 receive first attention. It has also 

 been demonstrated that certain 

 insects are attracted by a particular 

 colour, and choose this in pre- 

 ference to others. Thus, from 

 the experiments of Lord Avebury it 

 appears that bees will, if there should 

 be any choice in the matter, select the 

 blue flowers, while flies seem to be more 

 partial to those of a yellow or brown 

 tint. 



Many species with insignificant blooms 

 have called to their aid showy bracts to 

 advertise the presence of their flowers. 

 Of these, the South American Poinsettia 

 is one of the most striking examples. In 

 this case the true flowers are unattractive 

 and would certainly never be noticed on 

 their own merits. However, the flaming 

 red bracts which encircle the small 

 blossoms are so imposing that there are 

 few more striking sights than the Poin- 

 settia in perfection. In the same way 

 the Bougainvilleas have emphasised their 

 small dull yellow blossoms by encircling 

 them in three bright pink bracts. As a 

 result this plant is quite one of the most 

 showy features of the tropical forests. 



Many flowers are favoured with atten- 

 tion owing to the resemblance they bear 

 to some object which the insect is likely 

 121 



POISSETTIA I'ULCHERRIMA, FROM SOUTH AMERICA. 



The bracts surrounding the insignificant flowers are 

 flaming crimson in colour. 



to regard with favour. Nearly all flies 

 are fond of visiting rotting meat or 

 similarly offensive matter, and this 

 tendency has been taken advantage of 

 by many plants. The simulation is kept 

 up, both in the appearance of the bloom 

 and in the smell which it emits. The 

 British Field Iris has been called the 

 " Roast Beef Plant," owing to the curious 

 odour which the flower gives out, although 

 the smell is scarcely so appetising as 

 that of the cooking joint. A Southern 

 European Arum (^-1. dracunculus) is so 

 offensively scented that the plant is 

 hardly a fit subject for culture in the 

 garden. Moreover, the tinting of the 

 flower is of a lurid brown colour, not 

 unlike the colouring of rotting meat. 

 Most remarkable of all, however, are the 

 South American Aristolochias, plants 

 mostlv producing huge flowers coloured 

 in brown and white. The form of the 

 flowers of these Aristolochias is also very 

 singular, and in one species long portions 

 trailing away from the body of the bloom 

 give the impression of drippings from a 



