OBSERVATIONS ON INSECT LIFE 187 



forgotten habits as it is in the fragments of now worth- 

 less structures, that we can to-day review the past 

 incidents and changes which have influenced the course 

 of organic Hfe. 



Another plant visited by the humble-bees with 

 untiring energy is the pretty little yellow balsam, 

 Impatiens scabrida. Both the humble-bees, B. tuni- 

 catus and B. hcEmorrhoidalis, used freely to fertilize 

 this balsam. The size and form of the bell-shaped 

 flowers are beautifully adjusted to that of the humble- 

 bees. There is just sufficient room for the bee to 

 squeeze itself into the interior of the bell beneath 

 the overhanging anthers, and in so doing it covers 

 the upper surface of its thorax with a coat of viscid 

 pollen. When the flower first opens the pistil is 

 enclosed within the compact bunch of stamens and 

 is thus hidden from view, but later, when the petals 

 begin to shrivel, the stamens fall away so as to expose 

 the mature stigma and bring it in contact with the 

 pollen-stained thorax of every fertilizing bee. 



As in the case of the Strobilantktis, the bees secure 

 their nectar from this flower also by two methods, 

 either by perforating the corolla or by pushing down 

 into the interior of the bell. It is an advantage to the 

 plant if the bees enter the blossom, since in this way 

 they distribute the pollen and fertilize other flowers. 

 It is an advantage to the bees if they perforate the 

 corolla, as by this means they secure the nectar by an 

 easier and shorter route. But this must be only a 

 temporary gain ; in the end they would also be the 

 losers, since they would be deprived of their nectar by 

 fertilizing no flowers. 



Thus there is a ceaseless competition between the 



