NEPENTHES. 



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had to do double duty with their leaves. The basal portion 

 carried out the function of ordinary leaves, while the swollen and 

 pitcher-like apical portion was specially modified for the entrap- 

 ping and decomposition and digestion of insect food. Thus we 

 see that the complete leaf of a Nepenthes has " two strings to 

 its bow," and was enabled to exist under peculiar conditions of 

 specialised adaptation to peculiar circumstances and environ- 

 ment. Mr. Veitch had pointed out very clearly that Nepenthes 

 pitchers in a half-grown state, and before their lids opened, had 

 the power of secreting a limpid fluid, with a slightly acid taste, 

 and a weak odour of roasted apples, due to the malic acid the 

 fluid naturally contained. This fluid has been analysed and is 

 found to contain pepsine in appreciable quantities, so that it is a 

 true digestive fluid analogous to that of our own gastric juice, 

 and there are glands inside Nepenthes pitchers towards their 

 base which are also analogous to the secretive and absorptive 

 villi of the human stomach. In a word, the peptonised fluid 

 found in Nepenthes urns is specialised for digestive purposes 

 just as is rennet, or as are the peptonised elements found in fresh 

 ripe figs, both long known, and world-wide aids to digestion. 

 N. ampullacea is the only Nepenthes that has not honey glands 

 to attract insects. Mr. Burbidge next pointed out the way 

 insects were attracted to the urns of Nepenthes by a sugary or 

 honeyed secretion near the rims or mouths of the pitchers. This 

 honey, and perhaps also the odour of the peptonised fluid, 

 attracted many kinds of honey-eating insects, which became 

 caught inside the eel-trap-like ascidia. Then decomposition and 

 digestion began, and a rich and nutritious sort of soup was the 

 result. Another thing now occurred, viz., the odour of the 

 decomposing fluid and dead flies became again an attraction for 

 carnivorous or flesh-eating insects, and so a second harvest of 

 victims was secured. Apart from honey-eating and flesh- or 

 carrion-eating flies, there are other insects caught, such as beetles, 

 cockroaches, wood lice, gnats, wasps, daddy long-legs ; and ants 

 innumerable are found in the urns of Nepenthes both in Borneo 

 and here in hothouses at home. The formic acid of the ants 

 caught so universally no doubt plays a most important part in 

 intensifying or augmenting the action of the malic acid normally 

 present in the peptonised fluid or gastric juices secreted by these 

 plants as above shown. Of course the ferments set up by both 



