POLLIXA TION. 



437 



about the ?ame level as the stigma of the former. What does this interesting 

 relation of the stamens and pistils in the two different flowers mean ? As the 

 butterfly thrusts its "tongue" down into the tube of the long-styled flower 



Fig. 4.5 s. 

 Dichogamous flower of the bluet (Houstonia c^xrulea), the long-styled form. 



for the nectar, st^me of the pollen will be rubbed off and adhere to it. When 

 now the butterfly visits a short-styled flower this pollen will lie in the right 

 position to be rubbed off onto the stigma of the short style. The positions of 



Fig. 4S6. 

 Dichogamous liower of bluet * Houstonia cttnilea '. tlie short-st^-led form. 



the long stamens and long style are such that a similar cross pollination will 

 be effected. 



850. Pollination of tne primrose. — In the primroses, of which we have 

 examples growing in conser%'atorie5. that blossom during the winter, we 

 have almost identical examples of the beautiful adaptations for cross polli- 

 nation by insects found in the bluet. The general shape of the corolla is 



