138 From Matter to Man. 



on entering the flower strikes the empty end of the 

 cross-bar with its head, tilts it over, unconsciously tips 

 the pollen on its own back, and then so loaded, flies 

 away and fertilises another flower : for the stigma of 

 the orchid brushes off the pollen on the insect's 

 entrance, and so becomes fertilised. 



In the catasetum, when a bee lands on the labellum 

 of a male plant, a sensitive projection is touched ; 

 this in turn ruptures a certain membrane, which again 

 sets free a spring, and this spring automatically shoots 

 a mass of pollen on the bee's back. This pollen is 

 brushed off on the next female plant visited. In our 

 native orchids, although hermaphrodite, the pollen 

 does not fertilise its own stigma, for Darwin dis- 

 covered the pollinia sticking by viscid disks to the 

 heads of visiting butterflies and moths. These pollinia 

 thus fertilise the stigma of the next flower entered. 

 The process, however, is all automatic, not intention- 

 ally performed by either butterfly or flower, for if a 

 fine pencil be inserted into the orchid the pollinia 

 adhere also to it. The plant thus possesses no dis- 

 crimination ; its intelligence is solely automatic, and 

 is the result of ages of imperceptible modifications, 

 automatically developed by it in its automatically 

 going machinery. 



The large orchid caryanthes displays the most re- 

 markable contrivance, in the shape of a bucket in its 

 labellum into which water is constantly dropping from 

 secreting horns above. When half full, the water 

 overflows by a spout on one side. In the arch of the 



