Chap. V. BOLBOPHYLLUM. 137 



the flowers in the hothouse at Kew, for many eggs 

 were deposited within it, near the base. 



Of Bolbophyllum I examined the curious little 

 flowers of four species, which I will not attempt fully 

 to describe. In B. cwpreum and eocoinum, the upper and 

 lower surfaces of the rostdlum resolre themselves into 

 viscid matter, which has to be forced upwards by insects 

 into the anther, so as to secure the poUinia. I effected 

 this easily by passing a needle down the flower, which 

 is rendered tubular by the position of the labellum, 

 and then withdrawing it. In B. rhizophorse the anther- 

 case moves backwards, when the flower is mature, 

 leaving the two pollen-masses fully exposed, adhering 

 to the upper surface of the rostellum. They are held 

 together by viscid matter, and, judging from the 

 action of a bristle, are always removed together. The 

 stigmatic chamber is very deep with an- oval orifice, 

 which exactly fits one of the two pollen-masses. After 

 the flower has remained open for some time, the sides 

 of the oval orifice close in and shut the stigmatic 

 chamber completely, — a fact which I have observed in 

 no other Orchid, and which, I presume, is here related 

 to the much exposed condition of the whole flower. 

 When the two pollinia were attached to a needle or 

 bristle, and were forced against the stigmatic chamber, 

 one of the two glided into the small orifice more readily 

 than could have been anticipated. Nevertheless, it is 

 evident that insects must place themselves on suc- 

 cessive visits to the flowers in precisely the same 

 position, so as first to remove the two pollinia, and 

 then force one of them into the stigmatic orifice. The 

 two upper filiform petals would serve as guides to 

 the insect ; but the labellum, instead of making the 

 flower tubular, hangs down just like a tongue out of a 

 widely open mouth. 



