MR. J. P. M. WEALE ON A SOUTH-AFRICAN DISPERIS. 43 
minute account of its separate parts will be requisite for a com- 
plete understanding of its structure and the adaptation of its parts. 
Viewed laterally, the labellum presents in its front part a deep 
cup, the lip of which curves upwards at almost a right angle to 
the posterior portion, in such a manner that no insect could 
possibly reach its interior from the front—a difficulty which is 
increased by the outspread edges of the middle portion of the 
petals. Behind, the two sides of the cup rise backwards to a 
level with the top of the lip, and then spread behind and over 
the anther in an elongated somewhat oval appendage. On each 
side of the centre of the labellum two large membranous shield- 
like expansions, convex anteriorly and concave posteriorly, spread 
out and completely envelope the pollinia. The two narrow trans- 
verse divaricate stigmas, close to, immediately behind and on each 
side of the cup of the labellum, lie on the fleshy base of these ex- 
pansions, while immediately in front of them project the legs of 
the step-like rostellar processes. 
I will describe the relative situation of the anther and ros- 
tellum, on the supposition that the face of the flower is placed 
vertically—a position, however, which it does not assume in na- 
ture. The two steps of the rostellum would then lie in a plane 
parallel to the face of the flower, and nearly at right angles to 
the legs. The legs, again, would be placed at right angles to the 
pollen-masses ; and as the long slender caudicle follows the direc- 
tion of the leg-like processes, it is evident that in its natural po- 
sition it is doubly bent, somewhat like a reversed S or a Z. The 
foot or step of the rostellum is broad in front and tapers behind, 
somewhat like an isosceles triangle with rounded angles. The 
membranous edges curve slightly inwards, and resemble a lady's 
stirrup with very broad toes. 
Each is curved slightly outwards; and the edges of its mem- 
brane are also curled in, to retain the caudicle in its place. The 
viscid disk is an elongated thin membrane of nearly the same 
shape as the stirrup or step, and viscid on its upper surface; the 
caudicle arises from its narrow inner edge. 
I examined this flower for some time before I could make out 
how it could possibly be fertilized by an insect; and the difficulty 
was increased by my holding the flower vertically as above de- 
scribed. In nature the flower is bent down in a nearly hori- 
zontal position; the blades of the two sepals extend, on the 
contrary, in nearly opposite planes. 
