Chap. II. IIABENAEIA BIFOLIA. 73 



110 doubt is that the viscid discs cannot adhere to 

 a scaly or very hairy surface; the scales themselves 

 being easily detached. Variations in the structure of 

 the flower of an Orchid, unless they led to the viscid 

 discs touching some part of the body of an insect 

 where they would remain firmly attached,- would be of 

 no service, but an injury to the plant ; and consequently 

 such variations would not be preserved and perfected. 



Hahenaria lifolia, or Lesser Butterfly Orchis. — I am 

 aware that this form and the last are considered by 

 Mr. Bentham and by some other botanists as mere 

 varieties of one another ; for it is said that intermediate 

 gradations in the position of the viscid discs occur. 

 But we shall immediately see that the two forms 

 differ in a large number of other characters, not to 

 mention general aspect and the stations inhabited, with 

 which we are not here concerned. Should these two 

 forms be hereafter proved to graduate into each other, 

 independently of hybridisation, it would be a remarkable 

 case of variation ; and I, for one, should be as much 

 pleased as surprised at the fact, for these two forms 

 certainly differ from one another more than do most 

 species belonging to the same genus. 



The viscid discs of the Lesser Butterfly Orchis are 

 oval, and face each other. They stand far closer 

 together than in the last species ; so much so, that in 

 the bud, when their surfaces are cellular, they almost 

 touch. They are not placed so low down relatively to 

 the mouth of the nectary. The viscid matter is of 

 a somewhat different chemical nature, as shown by 

 its much greater viscidity, if after having been long 

 dried it is moistened, or after being kept in weak 

 spirits of wine. The drum-like pedicel can hardly be 

 said to be present, but is represented by a longitudinal 

 ridge, truncated at the end where the caudicle is 



