African and Madagascar Flowering Plants. 379 
of a bent bristle. On entering another flower the pollinia will 
be left in the ditch or pit, the sides of which are stigmatic. 
Visitors : — I found a male Nectarinia souimanga sucking the 
flowers, and certified that it removed at least one pollinium, 
but as the flowers are scented at night it is probably chiefly 
fertilised by night-flying moths, such as the Sphingidae (of 
whom some have proboscides eighteen inches long or more). 
Cf. Moore (Muller, No. 537), Darwin (Muller, No. 165). 
Disperis villosa, Swartz (Figs. 130-133). 
In this form the posterior sepal and the lateral petals are 
connate into a galea which has almost exactly the shape of 
a poke-bonnet (Salvation Army type). The anterior sepals 
spread out diagonally in front. The labellum has a narrow 
thread-like basal portion, and ends in a slightly thickened 
boat-shaped extremity which appears to secrete a sweet sub- 
stance. It is bent upwards and then folded back at a right 
angle so that this thickened extremity lies inside the galea 
and upon the top of the column. The column ends in the 
large anther-case, which is horizontal and reniform in shape. 
The end of the labellum lies in the groove of this reniform 
anther. The most striking peculiarity of the flower is the 
manner in which the anther-case terminates at both ends in 
front. The membrane of the anther-case at each anterior 
point is drawn out into a spiral ribbon which projects out 
of the opening to the galea, and is about two lines long : these 
two little coils stand further forward than the labellum which 
lies between them, and are close to one another. The cau- 
dicle of the pollinium lies along the inner side of their coils, 
and its disc is on the under surface of the extremity at d (Fig. 
131). In consequence of this arrangement, the readiest way 
for an insect to reach the honey secreted on the upper surface 
of the thickened end of the labellum (point n, Fig. 132) is by 
passing its proboscis under the arching extremity of the coil, 
i.e. below the disc. In doing this, it must search for the 
nectary by bending its proboscis about, and cannot fail to 
touch the disc, which immediately clasps it firmly. On 
