70 THE ORCHIDS OF NEW ENGLAND. 



rotation was detected. The throat of the flower is a narrow 

 chamber ; and the narrow stigma and the discs lie so low in it 

 that fertilization cannot be effected without insect aid, and this 

 can be given only by means of a proboscis. We find accord- 

 ingly, that a pig's bristle cannot be thrust down to the bottom 

 of the spur and withdrawn without bringing away one of the 

 pollen-masses. But the anther-cells open early and the pollen- 

 masses are often dislodged as soon as the flower opens. Yet 

 from the arrangement of the parts, we think that they can 

 never fall over upon their own stigma as they do in the 

 allied 



" Platanthera (Habcuaria) hyperborca. Here the lip, spreading 

 from the base, leaves a more open throat, the more exposed 

 stigma is broad and transverse, the anther-cells are more diver- 

 gent, and from the curvature of the flower, more overhanging, 

 and the stalks of the pollen-masses very slender and weak. 

 Thus disposed, the pollen-masses very commonly fall out of the 

 anther-cells while the tip of the lip is still held under the point 

 of the upper sepals and petals, or even in the closed buds, and 

 when the lip is disengaged and becomes recurved, or even be- 

 fore, the pollen-masses are apt to topple over and fall upon the 

 broad stigma beneath." In this respect the plant is much like 

 Ophrys opifcra in Darwin's treatise, but H. hyperborca is also 

 fertilized by outside aid. " The packets of pollen are looser 

 and the threads that attach them to the stalk weaker than 

 usual ; while the discs (which are oval and rather small) retain 

 for a good while their viscidity, so that a fitting insect on visit- 

 ing the open flowers, in which the pollen-masses have already 

 fallen over on to the broad stigma underneath, will yet catch 

 one or both of the discs upon his proboscis, carry off the pol- 

 len-masses (which may be readily detached from the stigma, 

 leaving some pollen behind) and apply them in succession to 

 the stigmas of other flowers of other individuals, and thds 

 effect occasionally the crossing so uniformly effected in most 



