SECT. 



BEE OPHRYS. 



397 



leaves pollen grains on it. There can be no doubt that 

 this plant is visited occasionally by insects, as it can- 

 not be fructified without them ; but it is scentless, and 

 as no nectar has as yet been found in it, their motive 

 for visiting it is unknown. 



The fructification of the Ophrys apifera, or Bee Ophrys, 

 is independent of insects, for the stalks of the pollinia 



Fig. 83. Epipactis palnstris : Side views of flower, with lower sepals cnt away : A, with 

 Hp in natural position ; B, with lip depressed as by an insect. 



are extremely long, thin, and flexible; and although 

 their viscid discs still remain in their pouches, as soon 

 as the flower expands, and the anther cells or pouches 

 open, the heavy thick ends of the pollinia fall out of 

 their cells, and hang freely down in the air exactly 

 opposite to the stigmatic surface. A breath of air is 

 sufficient to make them vibrate, strike the stigma with 

 their pollen mass, and leave pollen grains on its sticky 

 surface. 



The great tribe of British Neottese is characterized by 



