PITCHER-PLANTS. 105 



senting a tissue of different character. The difference 

 of structure in these two forms of pitcher, considered 

 in reference to their different positions on the plant, 

 forces the conclusion on the mind that the one form 

 is intended for ground game, the other for winged 

 game. In all cases the mouth of the pitcher is 

 furnished with a thickened corrugated rim, which 

 serves three purposes : it strengthens the mouth, and 

 keeps it distended ; it secretes honey, and it is in 

 various species developed into a funnel-shaped tube, 

 that descends into the pitcher, and prevents the 

 escape of insects, or into a row of incurved hooks, 

 that are in some cases strong enough to retain a 

 small bird, should it, when in search of water or of 

 insects, thrust its body beyond a certain length into 

 the pitcher. In one species {Nepenthes bicalcaratd), 

 there are also two strong pointed hooks, or teeth, 

 which are directed downwards towards the mouth 

 of the pitcher. Such appendages would doubtless 

 be of service in preventing the free exit of any 

 large insect after it had once entered the pitcher 

 (see fig. 11). 



The attractive surfaces of Nepenthes are two, those 

 namely of the rim of the pitcher, and of the under 

 surface of the lid, which is provided in almost every 

 species with honey-secreting glands, often in great 

 abundance. It is a singular fact that the only species 

 known to the writer of these observations, in which 



