106 ORCHIDS IN SARAWAK. 



dropped on to the labellum in another case the pollinia cap had 

 become detached and had caught on the stigmatic surface. 

 Nevertheless no relationship can be found between the rainfall 

 and fertilisation, and though self-fertilisation through the 

 agency of storms is not the usual mode yet it may occasionally 

 happen as the stigma is receptive to pollinia of the same flower. 



It should be mentioned that the butterfly Erionota thrax, 

 which effects the fertilisation of Arundina speciosa in Sarawak 

 is a common insect in Java. 



A few structural abnormalities were observed in these 

 flowers : in one case half the labellum was normal and the 

 other half was petaloid : in no less than three cases there were 

 supernumary pollinia on the column each having a distinct 

 pollinia cap. But there were no variations in the direction of 

 auto-fecundation. 



In a few isolated cases we have observed bees engaged on 

 the flowers of orchids which have no fragrance : for instance 

 Renanthera maingayi and alba of large showy but scentless 

 flowers commonly cultivated in Sarawak are rarely fertilised 

 and we have never seen insect visitors at the flowers but the 

 Rev T . John Perham assures us that the carpenter bees occasion- 

 ally visit the flowers of R. maingayi : and on one occasion, at 

 6 p. m., we saw a single specimen of the bee apis dorsita very 

 busy at the flowers of a large Cymbidium and the bee was 

 found to have pollinia on the metathorax and yet these flowers 

 are of dull red colour and are scentless. 



