191 



All the sepals at this stage are similarly narrowly ovate, the 

 lateral sepals being asymmetrically so. The lateral petals are 

 linear, and curved round the column to meet at their tips. The lip is 

 nearly as broad as long, cu-pidate above its broad shoulders, with the 

 margins in the lower part frilled and turned under. If these margins 

 be uncurved it will be seen that they are the lateral lobes of the lip. 

 Under each broad shoulder a wart has begun to form : three lateral 

 nerves end close to each of these warts. 



Between this stage of the bud and maturity the following 

 changes take place. The contiguous halves of the lateral sepals 

 thicken from the middle upwards ; the cuspidate tip of the lip turns 

 back, its shouldt-rs enlarge and the warts become sharp little upstand- 

 ing cones, while the side lobes increase along their margins so that 

 they are too full for the space that they have and towards the base of 

 the lip tend to form an upstandimtr rounded cre^t. 



Two very fleshy bodies, beinu the staminodes, lie within the 

 curve of this crest, one on each side. 



The opening of the flower takes place late in the afternoon or in 

 the early part of the night. In it, as a commencement, a slit appears 

 between the lateral sepals from the middle, downwards first, and 

 then to the tip. Next these lateral sepals break away and slowly 

 take a position at right angles to the ovary, and their thickened areas 

 begin to become convex inwards and thr av the thin parts back. 

 Following this movement the lateral petals rapidly elongate, curving 

 over strongly so that their points pass between the bases of the 

 lateral sepals, and in this curious action they deflex the lip on its 

 base holding it down against a certain amount of resistance, in con- 

 tact with the lateral sepals. Thus the flower gapes somewhat. 



If in the early stage of the flowering, the lateral petals are cut, 

 the lip springs up elastically against the column, being forced up 

 by the turgid tissue at its base and perhaps in less measure by the 

 pull of the margin. Meanwhile the dorsal sepal has not moved. 



This is the first stage of the flower and lasts into the night. It 

 is accompanied by the development of two eccentricities: one of 

 these is a movement of the column towards the right hand side of 

 the flower (right hand of an observer facing the flower), whereby later 

 it comes into contact with the shoulder of the lip; the other is the 

 unequal curving of the lateral sepals, the upper carving most, 

 whereby they come to form a platform with their swollen areas 

 presented forwards and upwards, and one, the upper, presses on the 

 tip of the labellum. The bilateral symmetry which was present in 

 the bud is now completely lost. 



During the night the second stage comes on, beginning with the 

 turning back of the dorsal sepal, i.nd continued by the straightening 

 of the lateral petals. The upper of the lateral sepals no longer held 

 away from its fellow by the lateral petals, now moves down to be in 

 contact with it, and is thus almost median as regards the lip, and as 



