1885.] INSECTIVOROUS PLANTS. 193 



INSECTIVOROUS PLANTS. 



r.Y KOBEKT LIXDSAY, CUrxATOE, ROYAL BOTANIC G^VEDEN, EDINBUEGH. 



Part I. 



OXE of tlie great distinctions between plants and animals whicli 

 was formerly held, was that plants lived on inorganic, while 

 animals lived on organic food. That distinction, however, breaks 

 down in various ways ; for instance, the very large group of plants 

 known as funffi live exclusively upon organic matter. It was also 

 said that animals were capable of consuming solid food, wMle plants 

 were not : this is also incorrect. Animals take solid food into the 

 mouth and stomach, but before it can be assimilated it must first 

 become liquid. Insectivorous plants have the power of taking solid 

 food into a structure which we are justified in calling a stomach. 

 The principal families in which there are plants possessing this 

 remarkable power are the Nepenthaceaj, Sarraceniacese, Droseracese, 

 and Utriculariace;e. 



THE NEPENTHES OR PITCHER-PLANT FAMILY 



consists of over thirty different species, besides an increasing number 

 of hybrids. They are half-shrubby climbing plants, natives of the 

 hotter parts of the Asiatic Arcliipelago, from Borneo, whicli is their 

 headquarters, to Ceylon, with a few outlying species in New Cale- 

 donia, in tropical Australia, and in the Seychelle Islands. The 

 pitcher of Nepenthes, which is its most strilcing feature, is an 

 appendage of the leaf, developed at its apex, and is furnished with 

 a stalk, often a very long one. This stalk, in the case of pitchers 

 formed high up on the stem, has, before full development, the power 

 of twisting like a tendril round neighbouring objects ; and thus the 

 plant climbs sometimes to a great height in the forests. In some 

 species the pitchers are of two forms, one appertaining to the young, 

 the other to the old state of the plant ; the transition being gradual 

 from the one to the other. Those of the young condition are shorter 

 and more inflated than in the old, where they are long and funnel- 

 shaped. In all cases the mouth of the pitcher is furnished with a 

 thickened corrugated rim, which serves three purposes — 1st, It 

 strengthens the mouth and keeps it distended ; 2nd, It secretes 

 honey ; and Srd, It forms a row of incurved teeth, which descend into 

 the pitcher and prevent the escape of insects. In some species 

 this row of teeth is strong enough to retain small birds, should they 

 thrust their body beyond a certain length when in search of insects; 

 even rats are said to have been found captured in some of the larger 



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