110 NEOTTE/E. Chap. IV 



summit of the pollinium. The leaves are very brittle, 

 and, when placed on the adhesive stigma, large pieces 

 are easily broken off. 



Long before the flower expands, the antlier-cells, 

 which are pressed against the back of the rostellum, 

 open in their upper part, so that the included pollinia 

 come into contact with the back of the boat-formed 

 disc. The projecting threads then become tirmly 

 attached to rather above the middle part of the back 

 of the disc. The anther-cells afterwards open lower 

 down, and their membranous walls contract and be- 

 come brown ; so that by the time the flower is fully 

 expanded the upper part of the pollinia lie quite 

 naked, with their bases resting in a little cup formed 

 by the withered anther-cell, and laterally protected by 

 the clinandrum. As the pollinia thus lie loose, they 

 are easily removed. 



The tubular flowers are eletrantlv arrano'ed in a 

 spire round the spike, and project from it horizontally 

 (iig. A). The labellum is channelled down the middle, 

 and is furnished with a reflexed and fringed lip, on 

 which bees alight ; its basal internal angles are pro- 

 duced into two globular processes, which secrete an 

 abundance of nectar. The nectar is collected (n, fig. 

 B) in a small receptacle in the lower part of the 

 labellum. Owing to the j)rotuberance of the inferior 

 margin of the stigma and of the two lateral inflexed 

 nectaries, the orifice into the nectar-receptacle is 

 much contracted. Whep the flower first opens the 

 receptacle contains nectar, and at this period the 

 front of the rostellum, which is slightly furrowed, 

 lies close to the channelled labellum; consequently 

 a passage is left, but so r arrow that only a fine bristle 

 can be passed down it. In a day or two the column 

 moves a little farther from the labellum, and a widei 



