SOME STRANGE GREENHOUSE PLANTS 



while the habitat of this giant relative is the 

 tropics, by the side of the mighty Amazon, and the 

 numerous lakes formed from the world's largest 

 river. 



Another wonderful example of adaptation of 

 leaves to suit particular circumstances is shown in 

 the curious and interesting Pitcher-plant (Nepen- 

 thes), of Indo-Malaysia (Fig. ']2y Plate 49). These 

 plants grow in boggy soils, where nitrogenous food 

 is difficult to obtain : the soil not being able to 

 supply the wants of the plant in this direction, the 

 plant has to seek elsewhere. So we find the 

 leaves developing at their ends curious pitchers o' 

 vessels, the interior walls of which are lined w^ith 

 glands which secrete a powerful digestive fluid. 



Around the mouths of these pitchers a sticky, 

 sweet substance is secreted as a bait to lure flies 

 and other insects into che interior, from which 

 they cannot return -wing to recurved spines 

 forming a barrier, ii^'inally, such entrapped in- 

 sects become exhau,,ced, and are drowned in the 

 liquid, their substanc j being then absorbed into the 

 plant tissues. Thus the pitcher-plants obtain their 

 nitrogenous food, and make up for the natural 

 deficiency of the soil. 



Still more novel is the epiphyte orchid shown 

 in Fig. 73 (Plate 50). Here we have a plant 

 that seems to possess quite original ideas as to 

 how it should develop — which, in fact, seems 

 almost to have reversed all the normal conditions 

 that govern plant life. Its roots, on a piece 01 

 dry bark, spread, it will be seen, in the air, instead 



103 



