44. MR. J. P. M. WEALE ON A SOUTH-AFRICAN DISPERIS. 
Let us suppose an insect to visit these flowers, as is proved by 
the fact of their producing numerous fertile capsules. It would 
most probably alight on the lateral sepals and suck some nectar 
from their little nectaries. It would then probably try to reach 
the cup-like labellum in the interior of the flower, in order to 
drink the more copious supply of nectar which lies in the cup. 
If it crawled up towards the base of the sepals, it would pro- 
bably, unless very small, find no footing on the narrow blade, 
nor could it enter the galea at this point, as the petals, as before 
stated, taper away to their junction with the broad fluted column 
and labellum which fill up the whole of the centre of the 
galea. 
The stirrup-like processes of the rostellum, however, stand out; 
and their broad feet would form a convenient landing-place 
especially suitable for a small Hymenopter or Dipter. In trying 
to enter thence the two chambers which open on either side 
of the labellum, its feet would stick to the viscid disk, and the 
long elastic caudicle would prevent its forward progress. In 
trying to rid itself of the incumbrance it would doubless with- 
draw the pollinium or pollinia; and were it again to attempt an 
entrance, their projecting faces would strike against the column 
and prevent ingress. Under these circumstances the insect 
would probably fly away to another flower, and whilst doing so, 
the pollinia would assume another position. In about a minute 
after removal the caudicle bends backwards, so that the pollen- 
mass lies above and behind the front part of the long viscid disk. 
Were the insect to alight then on a plant whose pollinia had 
already been withdrawn, it could easily enter the lateral cham- 
bers already mentioned, and could thence reach the nectar through 
the hollowed sides of the cup. In turning round to do this, the 
pollen-grains would almost certainly become attached to the 
stigma; or, as they adhere together but slightly, some would be 
knocked off against the dome, and would almost certainly fall on 
the stigma. 
I tried to fertilize this plant artificially by inserting a needle; 
but it was only by a good deal of awkward twisting that its ferti- 
lization could thus be effected ; and the utility of the movement 
of the caudicle was not apparent, as it was almost as easy 
to do it before the contraction had taken place. At the same 
time it was evident that no insect of considerable size could 
enter the side chamber; and I presume the fertilization is 
