APPENDIX 



Korthalsias occur — indeed, it is in their ant-shelters that the characters 

 are found which serve to distinguish the formicarian species of this most 

 difficult genus. 



Amongst the Korthalsias one species surprised me when I first met 

 with it near my house on Mattang, because I could not at first account 

 for a peculiar noise which I made out to be coming from one of these 

 plants. It was a sonorous rustling sound, which I afterwards found was 

 produced by the passage of a colony of ants inhabiting the vesicular 

 organs and inflations of the Korthalsia, which, being by nature rigid and 

 dry, produced in a certain measure the effects of the resonators of a 

 stringed musical instrument. 1 



Amongst the hospitating plants in Borneo must also be included 

 Nepenthes bicalcarata, 2 one of the most marvellous species of that 

 singular genus, because to the already surprising structure of its pitchers, 

 it adds the prerogative of a formicarian plant. In its case the ants 

 inhabit the stalks sustaining the pitchers, which are enlarged and hollow 

 for the purpose. 



I could not ascertain whether any connexion exists between the ants 

 sheltered by N. bicalcarata and the insects which fall into its pitchers ; 

 nor was I able to verify what has been asserted by others, namely, that 

 the insects imprisoned in the pitchers attract that singular little lemur 

 Tarsius spectrum, said to show a desire to prey on insects so detained, 

 were it not prevented from introducing its head into the pitchers by the 

 two appendages in the shape of walrus-tusks, which protect their mouths. 



It is impossible not to marvel at the shape and distribution of all 

 the appendages which surround the rim of the pitchers or ascidia of 

 the Nepenthes. In this respect a Nepenthes which I found near Kuching, 

 and which Sir Joseph Hooker has distinguished with the specific name 

 of echino stoma, * deserves special mention. In it, instead of edges, 

 crests, or projections, the rim of the pitchers is fringed with rigid points 

 directed inwards towards the cavity, which must serve admirably to 

 lead insects to the very edge of the precipice, make them fall over, and 

 prevent their escape. 



It cannot be doubted that insects must be attracted towards and 

 induced to visit the pitchers of the Nepenthes, considering all the artifices 

 and inducements brought into play, the strange shape of the pitchers, 

 their bright colours, and, above all, the glands disseminated around, 

 affording all kinds of sweetmeats, to tempt and lure the insects to perdi- 

 tion. Of this kind are the glands which are on the inner part of the lid 

 of the pitcher, where if a greedy and imprudent insect tries to rest, it 

 is almost certain to be trapped. But where Nature has shown all her 

 refinement of perfidy is in the disposal of these baits within and around 

 the rim of the pitchers. All the ornamental appendages, grooves, 

 enlargements, rings, points, etc., found there, have no other end than 

 that of leading the insects toward the lower inverted portion within 

 these appendages, where is a gland secreting nectar, placed in such a 

 position that if an insect reaches it, it almost certainly loses its balance 



1 Cf. Malesia, vol. ii., p. 62. 



2 Ibid., vol. ii., p. 231, pi. 55. 



3 Ibid., vol. iii., p. 27. 



407 



