On Flowers and Insects. 123 



Secondly, even when the stamens and pistil are 

 in the same flower, they are in many species not 

 mature at the same time; this was first observed 

 by Sprengel as long ago as 1790; in some cases 

 the stigma has matured before the anthers are ripe, 

 while in other and more numerous cases the anthers 

 have ripened and shed all their pollen before the 

 stigma has come to maturity. 



Thirdly, there are many species in which, though 

 the anthers and stigma are contained in the same 

 flower and are mature at the same time, they are 

 so situated that the pollen can hardly reach the 

 stigma of the same flower. 



5. The transference of the pollen from one flower 

 to another is, as already mentioned, effected princi- 

 pally either by the wind or by insects. 



Wind-fertilised 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. 



As a rule, wind-fertilised flowers produce much 

 more pollen than those which are fertilised 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. 



6. Again, it is an advantage to wind-fertilised 



