10 ON FLOWERS AND INSECTS. [LECT. 



plant, rise to the surface and float about freely like 

 little boats among the female flowers. 



Wind- fertilized flowers as a rule have no colour, emit 

 no scent, produce no honey, and are regular in form. 

 Colour, scent, and honey are the three characteristics by 

 which insects are attracted to flowers. 



Again, as a rule, wind-fertilized flowers produce much 

 more pollen than those which are fertilized by insects. 

 This is necessary, because it is obvious that the chances 

 against any given pollen grain reaching the stigma are 

 much greater in the one case than in the other. Every 

 one, as already mentioned, has observed the showers of 

 yellow pollen produced by the Scotch Fir. 



Again, it is an advantage to wind-fertilized plants to 

 flower early in the spring before the leaves are out, 

 because the latter would catch much of the pollen and 

 thus interfere with its access to the stigma. Again, 

 in these plants the pollen is less adherent, so that it 

 can easily be blown away by the wind, which would be 

 a disadvantage in most plants which are fertilized by 

 insects. 



Again, such flowers generally have the stigma more 

 or less branched or hairy, which evidently must tend to 

 increase their chances of catching the pollen. 



Moreover, as Mr. Darwin has observed (Jour. Linn. 

 Soc., vol. viii. p. 176), there does not appear to be a 

 single instance of an irregular flower which is not 

 fertilized by insects or birds. 



The evidence derivable from the relations of bees and 

 flowers is probably sufficient to satisfy most minds that 

 bees are capable of distinguishing colours, but the fact 

 had not been proved by any conclusive experiments. I 



