196 THE ORCHID REVIEW. [JULY, 1911 
; FERTILISATION OF ANGULOA CLOWESII. 
A YEAR ago a question was asked about the fertilisation of Anguloa in a 
‘wild state, which elicited two or three interesting facts (O.R., xviii. p. 211). 
A flower of A. Clowesii has now been sent by Mr. E. Rogers, gardener to 
O. O. Wrigley, Esq., Bridge Hall, Bury, in the hope that we may be able 
to trace some connection between the structure of the flower and the way 
it is fertilised. It has been called the Cradle Orchid, because of the way 
the lip rocks backwards and forwards as its balance is upset by the move- 
ment of the flower in the hand, but from the fact that on the plant the 
scape is borne quite upright, and is very rigid, one must look to the 
mechanism of the flower itself for an explanation. We do not remember 
any record as to the particular insect which fertilises Anguloa, but from 
a variety of considerations we suspect it is some large bee, and we 
imagine that the globose sepals and petals and open mouth of the lip are 
intended to ensure that the visit should be effected in some particular way. 
We may attempt to follow the bee during its visit. It would obviously 
alight on the apex of the flower and enter the open mouth of the lip, anda 
little experiment suggests what would probably happen. The first thing 
would be that the lip would assume the open position, with the lip away 
from the column, but if a pencil be now passed slowly and lightly down 
the lip it will be found that before it has time to reach the bottom the 
balance will be upset, and it will suddenly assume the closed position, with 
the lip touching the column. If the action had been caused by a bee, or 
similar insect, it would have been precipitated against the column, 
probably displacing the anther cap and fixing the pollinia to the insect by 
means of the viscid gland, and on its visiting a second flower, and repeating 
the process, the pollen masses would come in contact with the viscid 
stigma, and thus the fertilisation of the flower would be effected. The lip 
is the only mobile part of the flower, and we must assume that it has been 
progressively modified for its specific use in the economy of fertilisation. 
It would be very interesting if someone would observe the plant in its 
native home, and ascertain what particular insect plays the part of 
transferring the pollen from flower to flower. It is only there that the 
mystery can be effectively solved. The plant does not seed in our 
collections, unless artificially fertilised, because of the absence of the 
necessary insect, just in the same way that Vanilla planifolia, so much 
grown as an economic plant, has to be artificially fertilised. In certain 
districts of Central America, however, where the plant has its home, this is — 
unnecessary, because there certain small bees of the genus Andrena perform 
the necessary office, These remarks apply to other species of Anguloa, 
except that A. Cliftonii differs in having a saccate base to the lip. 
