By ALEX. G. HAMILTON. 



19 



cushion-shaped, and covered closely all over with fine short hairs 

 (figs. 5 and 6), so that it is not unlike a hair-brush with a curved 

 surface. The corolla consists of five petals uniting in a tube. 

 Four of these have their free extremities extended in a plane at 

 right angles to the tube, and at the mouth of the tube each has a 

 variable number of appendages (fig. 9) forming a corona, and so 

 arranged as to leave an opening at what I may call the front of the 

 flower (fig. 4). The fifth petal (labellum) bends down along the 

 tube, and has a projection at each upper angle, evidently the same 

 as those on the upper petals. At first this is glandular, shining, 

 and soft, but on the flower opening the glands disappear or coalesce 

 so as to make the surface level and smooth, and the texture becomes 

 hard and leathery. The column grows out of the tube and then 

 bends over the neck and downwards between two of the upper 

 petals, lying between the appendages of the labellum, and along 

 the surface of it (fig. 3). It then bends upwards and outwards with 

 a slight twist. The first bend over the tube is the hinge on which 

 the column bends when moving, and is thicker and wider than 

 the parts above and below. It also has transverse ridges at this 

 point, which are coloured pink or crimson, while the other parts 

 of the column ai'e greenish or brownish-green. The whole of the 

 flower-stem, the calyx, and, to a slight extent, the backs of the 

 upper petals ai-e covered with sticky crimson-headed glandular hairs 

 or trichomes (fig. 8), the object of which is evidently to prevent 

 small crawling insects gaining access to the flower and robbing 

 the tube of its nectar, without any advantage to the plant. The 

 trichomes wither on the older flowers and capsules when the 

 necessity for them has passed away. 



The flower is fertilised by insects, and it is not self-fertile, as 

 may be seen from capsules withering from want of fertilisation, 

 while in a spike of flowers one or two may sometimes be fertilised 

 between flowers above and below which are not. 



The method of fertilisation is as follows : — Any insect such as 

 a bee, visiting the flower, selects the side where is the widest 

 opening between the petaline appendages; this is exactly opposite 

 the hinge or first bend of the column (a, figs. 4 &, 5), and this 



