I04 OUR NATIVE ORCHIDS 



its nectar that spiders build their webs over the blossoms to 

 catch them; so Darwin's son reported to his father, who 

 sent him forth to observe the insects that visited 

 them. 



Though none but the orchid hunter might notice the 

 characteristic shape of the leaves and the bird-like fluttering 

 of the blossoms of these little plants that rarely grow more 

 than a few inches high, yet they have had considerable 

 attention from the scientific world. 



The very learned Hooker described the structure and 

 action of the rostellum in Listera, but left out the part that 

 insects perform, and Sprengel, who fully appreciated the 

 fact that the construction was adapted to the visits of insects, 

 misunderstood the structure and action of the rostellum, 

 described just how they fertilised, and so failed to tell the 

 whole story. 



This Darwin did later, when he had fully established 

 the fact that the insects carry the pollen from one plant to 

 another. 



The three species of Listera which concern us have, in 

 addition to the pair of green leaves about the middle of the 

 stem, one or two small scales at the base of the stalk. The 

 flowers are somewhat scattered on a loose raceme that flowers 

 from its base up. They have no spurs, and the sepals and 

 petals look much alike. The anther has no lid and stands 

 erect, joined to the column, and has two powder}- pollinia 

 united to a very small gland. 



The fruit is in the form of an ovoid capsule, that, per- 



