Chap. II. OPHKYS MUSCIFEEA. 47 



as the viscid matter quickly sets hard when exposed to 

 the air. The pouch is not elastic, and does not spring 

 up when the poUinium is removed. Such elasticity 

 would have been useless, as there is here a separate 

 pouch for each viscid disc ; whereas in Orchis, after 

 one poUinium has been removed, the other has to 

 be kept covered up and ready for action. Hence it 

 appears that nature had been so economical as to save 

 even superfluous elasticity. 



The poUinia cannot, as I have often proved, be shaken 

 out of the anther-cells. That insects of some kind 

 visit the flowers, though not frequently, and remove 

 the pollinia, is certain, as we shall immediately see. 

 Twice I have found abundant pollen on the stigmas of 

 flowers, in which both pollinia were still in their cells ; 

 and no doubt this might have been much oftener ob- 

 served. The elongated labellum affords a good landing- 

 place for insects : at its base, just beneath the stigma, 

 there is a rather deep depression, representing the 

 nectary in Orchis ; but 1 could never see a trace of 

 nectar within it ; nor have I ever observed any insects 

 approach these inconspicuous and scentless flowers, often 

 as I have watched them. There is, however, on each side 

 of the base of the labellum a small shining projection, 

 having an almost metallic lustre, which appears curi- 

 ously like a drop of fluid or nectar ; and as these flowers 

 are only visited occasionally by insects, Sprengel's view 

 of the existence of sham-nectaries is far more probable 

 in this case than in any other known to me. On 

 several occasions I have detected minute punctures in 

 these protuberances, but I was not able to decide whether 

 they had been made by insects, or whether superficial 

 cells had spontaneously burst. Similar shining pro- 

 tuberances are present on the labella of all the other 

 species of Ophrys. The two rostella stand not far 



