62 OFIIIIE-E. Chap. II. 



finding tlirco (load insects, permanently glued to the 

 discs. Whilst sucking the nectar, which takes two or 

 three minutes, the projecting joint of the femur stands 

 under the large helmet-like viscid disc on either side ; 

 and when the insect retreats, the disc exactly fits on 

 and is glued to the prominent joint, or to the surface 

 of the femur. The movement of depression in the 

 caudicle now takes place, and the mass of pollen-grains 

 then projects just beyond the tibia ; so that the insect, 

 when entering another flower, can hardly fail to ferti- 

 lise the stigma, which is situated directly beneath the 

 disc on either side. 



Fig. 9. 



Pkristvlus viridis, op. Frog Orchis. 

 Frout view of flower. 



a. anther. i n',.'. lateral nectaries, 



s. stigma. /. labellnm. 



n. orifice of central nectary. I 



Peristtjlus viridis. — This plant, which bears the odd 

 Qame of the Frog Orchis, has been placed by many 

 botanists in the genus Habenaria or Platanthera; but 

 as the discs are not naked, it is doubtful whether this 



