of a few Orchids in Sarawak. 105 



the axils and could be carried long distances by violent winds. 

 It is evident then that orchids are not so much dependent on 

 cross-fertilisation for their propagation and dispersal as might 

 be supposed from a study of the floral structure alone. 



To return to Arundina speciosa : this has been under 

 observation for months and on one occasion only a bee visitor 

 was seen in the flowers. On Dec. 16.07 in the morning a 

 solitary bee (Apis dorsata) was observed to enter the flowers 

 of a large clump of this orchid : it visited about a dozen flowers 

 spending about half a minute in each flower. Eventually it 

 was captured and on the thorax posteriorly an accumulated 

 heap of pollinia had collected. It is probable therefore that 

 Arundina speciosa is occasionally fertilised by the agency of 

 bees but nevertheless this is such a rare visitor that we must 

 look elsewhere for the insect which is more usually responsible 

 for the fertilisation of Arundina speciosa. And this is 'found to 

 be the large skipper butterfly Erionota thrax which on certain 

 evenings at about 6 p. m. pass with rapid flight.- from flower 

 to flower spending a brief moment at each : sometimes pollinia 

 are removed but often this is not the case. Between the dates 

 Aug. 20.07 and Sept. 28.07 eleven plants were under careful 

 examination. During this time 224 flowers were produced 

 but only 15 capsules resulted. 



Fertilisation took place only between the dates Sept. 2 

 and Sept. 21 as follows : 



Sept. 2 1 flower Sept. 6 2 flowers 



Sept. 13 3 flowers Sept. 15 2 flowers 



Sept. 17 3 flowers Sept. 19 2 flowers 



Sept. 21 2 flowers 



During this time the Skipper butterfly was observed in 

 some numbers at dusk : the orchids which were fertilised were 

 adjacent to a group of Banana plants on the leaves of which 

 the caterpillars of Erionota feed. In this same period pollinia 

 were removed in no less than 29 observed cases (there may 

 perhaps have been more) : sometimes these were noticed after 

 heavy storms of rain and wind and in one case the pollinia had 



R. A. Soc, No. 54. 1909. 



