Chap. I. ORCHIS USTULATA. 25 



fly to another plant, and thus effect a nnion between 

 two distinct individuals. 



Orchis ustulata * resembles 0. pyramidalis in some 

 important respects, and differs from it in others. The 

 labellum is deeply channelled, and the channel which 

 replaces the guiding ridges of 0. pyramidalis leads to 

 the small triangular orifice of the short nectary. The 

 upper angle of the triangle is overhung by the ros- 

 tellum, the pouch of which is rather pointed below. 

 In accordance with this position of the rostellum, 

 ■close to the mouth of the nectary, the stigma is 

 double and lateral. This species shows in an interest- 

 ing manner how easily t\A0 distinct stigmas, like those 

 •of 0. injramiclalis, might be converted into a single 

 one, by becoming at first slightly lobed like that of 

 0. mascula, and then acquiring its present structure. 

 For directly beneath the rostellum there is a narrow 

 transverse rim, formed of true stigmatic tissue, which 

 •connects together the two lateral stigmas ; so that 

 if this rim were widened, the two stigmas would be 

 converted into a single transverse one. Conversely 

 a single stigma might thus easily be converted into a 

 double one. The pollinia undergo the usual move- 

 ment of depression, and in acquiring this position 

 the two diverge slightly, so as to be ready to strike the 

 two lateral stigmas. 



Orchis (sub-genus Himantoglossum) hireina. — A fine 

 specimen of this extremely rare British plant, the 

 Lizard Orchis, with its curious elongated labellum, 

 was sent me by Mr. Oxenden. The two pollinia 

 arise from a single almost square disc ; and when 



* I am gretitly indebted to IVIr. kindness in Buppljnng me -witn 

 G. Cliiehester Oxenden of Broome living plants, and information re- 

 Park for fresh specimens of this gnrding many of tlie rarer British 

 Orchis, and for his never-tiriug Orchids. 



