OPHEE^. 



Chap. IL 



Fig. 12. 



fore-shortened. 

 A. Disc and caudicle of //. hi 

 full I, seen from above. 



attached, and there is hardly a vestige of the rudi- 

 mentary tail. In fig. 12 the discs of both species, 

 of the proper proportional 

 sizes, are represented as seen 

 vertically from above. The 

 pollinia, after removal from 

 their cells, undergo nearly the 

 same movements as in the last 



B. Disc and caudicle of H. chlo- . t i J_^ n ji 



rantha, seen from above, SpCClCS. in both lorms the 



with tiie drum-like pedicel movement is wcll showu by 

 removing a pollinium by the 

 thick end with a pair of pin- 

 cers, and holding it under the microscope, when the 

 plane of the viscid disc will be seen to move through 

 an angle of at least forty-five degrees. The caudicles 

 of the ]^esser Butterfly Orchis are relatively very much 

 shorter than in the other species; the little packets 

 of pollen are shorter, whiter, and, in a mature flower, 

 separate much more readily from one another. Lastly, 

 the stigmatic surface is differently shaped, being more 

 plainly tripartite, with two lateral prominences, situ- 

 ated beneath the viscid discs. These prominences 

 contract the mouth of the nectary, making it sub- 

 quadrangular. Hence I cannot doubt that the Larger 

 and Lesser Butterfly Orchids are distinct species, 

 masked by close external similarity.* 



As soon as I had examined the present species. 



* Afconling to Dr. H. Miiller, 

 ITabenaria or Platanthera bifoUa 

 of Enslish authors is the P. sol- 

 stitialis of Boenuinghausen ; and 

 lie fully agrees with me that it 

 must be ranked as specifically 

 distinct from P. chlorantlia. Dr. 

 MuUer states tl)at this latter 

 species is connected by a series 

 of gradalions witJi another form 



which in Germany is called P. 

 hifolia. He gives a very full and 

 interesting account of the varia- 

 bility of these three forms of 

 Platanthera, and of their structure 

 in relation to their manner of fer- 

 tilisation : 'Verhandl. d. Nat. 

 Verein. f. Pr. Eh. u. Westfal' 

 Jahrg. XXV. III. Folge, v. Bd. pp. 

 36-38. 



