42 THE ORCHIDS OF NEW ENGLAND. 
was formed.” He mentions, however, one British species, 
Herminium monorchis, ‘which has two separate and large 
discs,” and also “a crest or solid ridge, more plainly developed 
than might have been expected; ” and have we not in our A. 
Hooker a similar instance ? 
“ Habenarta chlorantha depends,” says Darwin, “on the 
larger nocturnal Lepidoptera,’ and he shows the contrivances 
for securing fertilization to be even more interesting than in 
Orchis spectabilts. ‘The two anther cells are separated by a 
wide space of connective membrane, and the pollen-masses are 
enclosed in a backward, sloping direction. The viscid discs 
front each other and stand in advance of the stigmatic surface. 
Each disc is circular, and in the early bud consists of a mass of 
cells of which the exterior layers (answering to the pouch in 
Orchis) resolve themselves into matter which remains adhesive 
for at least twenty-four hours after the pollen-mass has been 
removed.” The stalk, or caudicle, of the pollen-mass does not 
rise directly out of the flat side of the viscid “ button,” like the 
stem on a cherry, but is attached to it by “a short drum-like 
pedicel or continuation of the membranous portion of the disc;” 
the shank of the button, to carry out the simile. This stalk is 
united “in a transverse direction to the embedded end of the 
drum, and its extremity is prolonged, as a bent rudimentary 
tail, just beyond the drum. The stalk is thus united to the 
viscid disc in a plane at right angles. The drum-like pedicel is 
of the highest importance, not only by rendering the viscid disc 
more prominent, but on account of its power of contraction. 
The pollinia lie inclined backward in their cells, above and some 
way on each side of the stigmatic surface: if attached in this 
position to the head of an insect, the insect might visit any 
number of flowers and no pollen be left,” the pollinia “striking 
against the anther-cells.” But in a few seconds after the pol- 
linium is removed “and the inner end of the drum-like pedicel 
exposed to the air, one side of the drum contracts and draws 
